Information processing device and method, and program, for  gamut conversion of content

ABSTRACT

An device, method and program may properly perform gamut conversion of content and be applied to a gamut conversion device. A restoration conversion state confirming unit performs confirmation such as gamut conversion state of image data read out from an optical disc and the existence or not of restoration metadata. An information exchange unit communicates with an output device via a communication unit and performs information exchange such as the existence or not of restoration processing functionality and gamut conversion functionality and the like. A determining unit determines whether or not restoration processing is performed with a playing device based on information obtained by the restoration conversion state confirming unit and the information exchange unit. Similarly, the determining unit determines whether or not to perform gamut conversion processing with the playing device based on information obtained by the restoration conversion state confirming unit and the information exchange unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.14/605,361, filed on Jan. 26, 2015 which is a continuation of U.S.application Ser. No. 13/320,081, filed on Nov. 11, 2011, issued as U.S.Pat. No. 9,001,140, which is a National Phase Filing ofPCT/JP2010/058080, filed on May 13, 2010, which claims the priority ofJapanese Patent No. P2009-124246, filed on May 22, 2009, the disclosuresof which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an information processing device andmethod and program, and in particular relates to an informationprocessing device and method and program wherein gamut conversion ofcontent can be performed more appropriately.

BACKGROUND ART

Conventionally, as a color space to indicate RGB data, there has been amethod that uses sRGB color space which is a standard color space formonitors. For example, upon JPEG (Joint Photographic Experts Group) datawhich is commonly used is opened on a personal computer, the sYCC datarecorded in the JPEG data is immediately converted to sRGB data. If dataoutside of the sRGB gamut exists in the sYCC data (i.e., negative valueor value above 256 with an 8-bit value), natural clip to the sRGB colorspace occurs, and color phase shift can occur.

Natural clip indicates a phenomenon wherein a color outside the gamut ofthe image data supplied externally is forcibly expressed with a colorwithin the gamut of the device. For example, in the case that only theR-component of a color shown with RGB is greater than the maximum valueof the R-component of the gamut, the R-component of the color thereof isexpressed with the maximum value of the R-component of the gamut(natural clip). At this time, the RGB balance of the original color islost due to this natural clip, and the hue changes. This type of huechange is called color phase shift. That is to say, the color isexpressed with a color different than the original color, so this sortof color phase shift occurrence is not favorable.

In order to prevent this, there is a method to perform gamut conversionwhich compresses the gamut of the image data into the sRGB gamut on therecording device side beforehand. With this gamut conversion, theoriginal sYCC data has already been compressed within the sRGB gamut, soeven if the JPEG data is opened and subjected to sRGB conversion, dataoutside the gamut is not generated. That is to say, the occurrence ofcolor phase shift as described above can be suppressed.

However, while sRGB represents the gamut of a standard personal computermonitor, there are portions that are decisively narrow when comparedwith the gamut of a printing device or wide gamut liquid crystaltelevision receiver (wide gamut liquid crystal TV) or the like.

FIG. 1 is a schematic diagram showing a comparison state of gamutranges. As shown in the example in FIG. 1, a gamut 1 of a general inkjetprinter is narrower than an sRGB gamut 2 in many hues, but many of theblue/green regions are wider. Also, a gamut 3 of a wide gamut liquidcrystal TV is generally wider that the sRGB gamut 2 in all hues.

However, once the gamut of moving picture content is converted to thenarrow sRGB gamut, information before compression that had beenoriginally recorded is lost. This information is then unable to beexpressed, regardless of the gamut of the output device. Expression isimpossible, even with a wide gamut liquid crystal TV having a widegamut. That is to say, with gamut conversion to a narrow gamut, imagequality of the moving picture content may unnecessarily be deteriorated.

Therefore, various methods to restore the data that has once beencompressed, and compress again into the gamut of the output device, havebeen proposed (e.g., PTL 1 and PTL 2).

PTL 1 discloses a method where barcode information showing profile datais printed onto paper along with the image, and by scanning the barcodeinformation thereof in the event of printing with a separate printingdevice, gamut compression is performed again for the separate printingdevice.

Also, PTL 2 discloses a method where information before compression ofthe compressed RGB data (maximum/minimum values, compression table, andthe like) is read in, image data is restored, and gamut compression isperformed again for the final output device.

SUMMARY OF INVENTION Technical Problem

However, in either PTL 1 or PTL 2, control of restoration processing orgamut conversion processing in a system made up of multiple devices arenot disclosed. Therefore, for example, in the case of an informationprocessing system wherein a recording device records content data to arecording medium, a playing device reads out the content data thereoffrom the recording medium and transfers this to an output device, andthe output device outputs the content thereof, which processing isperformed with which device is not defined, and gamut conversionprocessing and restoration processing may be performed unnecessarily.Thus, not only is the load increased unnecessarily, but image quality ofthe content can be reduced unnecessarily.

The present invention is proposed with consideration for such asituation, and enables gamut conversion of the content to be performedmore properly.

Solution to Problem

A first aspect of the present invention is an information processingdevice that has restoration metadata generating means to generaterestoration metadata that includes data referenced in restorationprocessing which returns at least a portion of the gamut of an imagesubjected to gamut conversion to the state before gamut conversion; andassociating means to associate the restoration metadata generated withthe restoration metadata generating means to the image.

The restoration metadata generating means can generate the restorationmetadata in the case that the image is a high tone image that is higherthan a predetermined tone.

A first aspect of the present invention is also an informationprocessing method that has a restoration metadata generating step togenerate restoration metadata that includes data referenced inrestoration processing which returns at least a portion of the gamut ofan image subjected to gamut conversion to the state before gamutconversion; and a step to associate the generated restoration metadatato the image.

A first aspect of the present invention is also a program that causes acomputer to execute an information processing method that has arestoration metadata generating step to generate restoration metadatathat includes data referenced in restoration processing which returns atleast a portion of the gamut of an image subjected to gamut conversionto the state before gamut conversion; and a step to associate thegenerated restoration metadata to the image.

A second aspect of the present invention is an information processingdevice that has communication means to perform communication of theimage subjected to gamut conversion between other information processingdevices; confirming means to confirm determining conditions forcontrolling the execution of restoration processing that returns atleast a portion of the gamut of the image to the state before gamutconversion; and control means to control execution of the restorationprocessing, based on the confirmation results by the confirming means.

The confirming means can confirm whether or not, as the determiningcondition, the information processing device itself and the otherinformation processing devices are each able to execute the restorationprocessing.

In the case that only the information processing device itself isconfirmed as able to execute the restoration processing, the controlmeans can cause the information processing device itself to execute therestoration processing.

In the case that only the other information processing device isconfirmed as able to execute the restoration processing, the controlmeans can cause the other information processing device to execute therestoration processing.

In the case that both of the information processing device itself andthe other information processing device are confirmed as unable toexecute the restoration processing, the control means can omit therestoration processing.

In the case that both of the information processing device itself andthe other information processing device are confirmed as able to executethe restoration processing, the control means can further confirm aselection condition for selecting a favorable device to perform therestoration processing.

The confirming means confirm whether or not, as the selection condition,the manufacturing source of the other information processing devicematches the information processing device; and wherein, in the caseconfirmation is made that the manufacturing source of the otherinformation processing device matches the information processing device,the control means can cause the other information processing device toexecute the restoration processing, and in the case confirmation is madethat the manufacturing source of the other information processing devicedoes not match the information processing device, the control means cancause the information processing device itself to execute therestoration processing.

The confirming means confirm whether or not, as the selection condition,the algorithm of the restoration processing of the other informationprocessing device is newer than the algorithm of the restorationprocessing of the information processing device; and wherein, in thecase confirmation is made that the algorithm of the restorationprocessing of the other information processing device is newer than thealgorithm of the restoration processing of the information processingdevice, the control means cause the other information processing deviceto execute the restoration processing; and in the case confirmation ismade that the algorithm of the restoration processing of the otherinformation processing device is not newer than the algorithm of therestoration processing of the information processing device, the controlmeans can cause the information processing device itself to execute therestoration processing.

The confirming means confirm whether or not, as the selection condition,the other information processing device is able to execute therestoration processing as to a high-tone image that is higher than apredetermined tone; and wherein, in the case confirmation is made thatthe other information processing device is able to execute therestoration processing as to the high-tone image, the control meanscause the other information processing device to execute the restorationprocessing; and in the case confirmation is made that the otherinformation processing device is not able to execute the restorationprocessing as to the high-tone image, the control means can cause theinformation processing device itself to execute the restorationprocessing.

The confirming means confirm whether or not, as the selection condition,restoration metadata exists which includes information necessary for therestoration processing of the image; and wherein in the caseconfirmation is made that the restoration metadata of the image exists,the control means can cause the information processing device itself orthe other information processing device to execute the restorationprocessing.

The confirming means further confirm a selection condition to select afavorable device for performing gamut conversion processing to convertthe gamut of the image to a desired gamut; and wherein the control meanscan control execution of the gamut conversion processing, based onconfirmation results by the confirmation means.

The confirming means confirm whether or not, as the selection condition,the manufacturing source of the other information processing devicematches that of the information processing device, whether or not thealgorithm of the gamut conversion processing of the other informationprocessing device is newer than the algorithm of the gamut conversionprocessing of the information processing device, or whether or not theother information processing device is able to execute the gamutconversion processing as to a high-tone image that is higher than apredetermined tone; wherein in the case confirmation is made that themanufacturing source of the other information processing device matchesthat of the information processing device, in the case confirmation ismade that the algorithm of the gamut conversion processing of the otherinformation processing device is newer than the algorithm of the gamutconversion processing of the information processing device, or in thecase confirmation is made that the other information processing deviceis able to execute the gamut conversion processing as to the high-toneimage; and wherein in the case confirmation is made that themanufacturing source of the other information processing device does notmatch that of the information processing device, in the caseconfirmation is made that the algorithm of the gamut conversionprocessing of the other information processing device is not newer thanthe algorithm of the gamut conversion processing of the informationprocessing device, or in the case confirmation is made that the otherinformation processing device is unable to execute the gamut conversionprocessing as to the high-tone image, the control means can cause theinformation processing device itself to execute the gamut conversionprocessing.

The information processing device further has playing means to read outthe image from a recording medium, wherein the confirming means confirma determining condition for controlling execution of the restorationprocessing as to the image read out from the recording medium by theplaying means; wherein the control means control the execution of therestoration processing as to aid image read out from the recordingmedium by the playing means, based on confirmation results by theconfirmation means; and wherein the communication means can transmit theimage read out from the recording medium by the playing means or animage subjected to control by the control means and the restorationprocessing, to the other information processing device.

The information processing device further has output means to output theimage, wherein the communication means receive the image transmittedfrom the other information processing device; wherein the confirmationmeans confirm determining conditions for controlling the execution ofthe restoration processing as to the image received by the communicationmeans; wherein the control means control the execution of therestoration processing as to the image received by the confirmationmeans, based on confirmation results by the confirmation means; andwherein the output means can output the image received by thecommunication means or the image controlled by the control means andsubjected to the restoration processing.

A second aspect of the present invention is an information processingmethod that has a step to perform communication of an image subjected togamut conversion between other information processing devices; a step toconfirm determining conditions for controlling the execution ofrestoration processing which returns at least a portion of the gamut ofthe image to the state before gamut conversion; and a step to confirmexecution of the restoration processing based on the confirmationresults.

A second aspect of the present invention is a program to cause acomputer to execute an information processing method that has a step toperform communication of an image subjected to gamut conversion betweenother information processing devices; a step to confirm determiningconditions for controlling the execution of restoration processing whichreturns at least a portion of the gamut of the image to the state beforegamut conversion; and a step to confirm execution of the restorationprocessing based on the confirmation results.

According to the first aspect of the present invention, restorationmetadata, including data that is referenced in the restorationprocessing that returns at least a portion of the gamut of the imagesubjected to gamut conversion to the state before gamut conversion, isgenerated, and the generated restoration metadata is associated to theimage.

According to the second aspect of the present invention, communicationis performed between other information processing devices about theimage subjected to gamut conversion, a defining condition forcontrolling execution of the restoration processing to return at least aportion of the image gamut to the state before gamut conversion isconfirmed, and based on the confirmation results, execution of therestoration processing is confirmed.

Advantageous Effects of Invention

According to the present invention, information can be processed.Particularly, gamut conversion of content can be performed moreproperly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a comparison state of gamutranges.

FIG. 2 is a diagram illustrating a configuration example of aninformation processing system to which the present invention is applied.

FIG. 3 is a block diagram illustrating a configuration example of therecording device in FIG. 2.

FIG. 4 is a block diagram illustrating a configuration example of theplaying device in FIG. 2.

FIG. 5 is a block diagram illustrating a configuration example of theoutput device in FIG. 2.

FIG. 6 is a flowchart describing an example of the flow of recordingcontrol processing.

FIG. 7 is a flowchart describing an example of the flow of playingdetermining processing.

FIG. 8 is a flowchart describing an example of the flow of playingcontrol processing.

FIG. 9 is a flowchart describing an example of the flow of gamutconversion control processing.

FIG. 10 is a flowchart describing an example of the flow of outputcontrol processing.

FIG. 11 is a flowchart describing an example of the flow of restorationconversion control processing.

FIG. 12 is a block diagram illustrating another configuration example ofthe playing device in FIG. 2.

FIG. 13 is a block diagram illustrating another configuration of theoutput device in FIG. 2.

FIG. 14 is a flowchart describing another example of the flow of outputcontrol processing.

FIG. 15 is a flowchart describing another example of the flow of gamutconversion control processing.

FIG. 16 is a flowchart describing another example of the flow of playingcontrol processing.

FIG. 17 is a flowchart describing another example of the flow ofrestoration conversion control processing.

FIG. 18 is a flowchart describing yet another example of the flow ofplaying control processing.

FIG. 19 is a flowchart describing yet another example of the flow ofoutput control processing.

FIG. 20 is a diagram illustrating a specific example of an informationprocessing system to which the present invention is applied.

FIG. 21 is a diagram illustrating an example of a format of chromaticityinformation.

FIG. 22 is a schematic diagram illustrating an example of a gamut.

FIG. 23 is a diagram illustrating an example of a Cusp table.

FIG. 24 is a flowchart describing an example of the flow of gamutconversion processing.

FIG. 25 is a diagram illustrating an example of a state of gamutconversion.

FIG. 26 is a diagram illustrating an example of an LU table.

FIG. 27 is a diagram illustrating an example of a conversion function.

FIG. 28 is a diagram illustrating an example of a saturation computingmethod.

FIG. 29 is a diagram to compare a gamut clip and the state of gamutconversion.

FIG. 30 is a diagram illustrating an example of a hypothetical clipborder.

FIG. 31 is a diagram illustrating a state of gamut conversion mapping.

FIG. 32 is a diagram illustrating an example of a restoration function.

FIG. 33 is a diagram illustrating an example of an isobestic pointtable.

FIG. 34 is a diagram illustrating an example of a recording format ofgamut metadata.

FIG. 35 is a diagram illustrating an example of a recording format ofrestoration metadata.

FIG. 36 is a diagram illustrating an example of the gamut of an outputdevice.

FIG. 37 is a flowchart describing an example of the flow of restorationprocessing.

FIG. 38 is a diagram illustrating a decision state of a restorationrange.

FIG. 39 is a diagram describing an example of a decision state of ahypothetical restoration border.

FIG. 40 is a diagram describing an example of a state of restorationmapping.

FIG. 41 is a block diagram illustrating a primary configuration exampleof a personal computer to which the present invention has been applied.

DESCRIPTION OF EMBODIMENTS

Modes for carrying out the invention (hereafter called embodiments) willbe described below. Note that description will be made in the followingorder.

1. First embodiment (control of playing device leading)2. Second embodiment (control of output device leading)3. Third embodiment (control of only gamut conversion)4. Fourth embodiment (main compression data control)5. Fifth embodiment (gamut conversion processing and restorationprocessing)

6. Sixth embodiment (personal computer) 1. First Embodiment DeviceConfiguration

FIG. 2 is a diagram illustrating a configuration example of aninformation processing system to which the present invention has beenapplied.

An information processing system 100 shown in FIG. 2 is a systemexecutes various types of processing relating to content (image data),such as generating image data by imaging or the like (or obtaining imagedata from outside of the system), recording image data serving as thecontent thereof to a recording medium, reading out (playing) image datafrom the recording medium, and displaying (output) images of the playedimage data, and together with these processes, more reliably andproperly performs restoration and gamut conversion of the image dataserving as content.

The information processing system 100 has a recording device 101,playing device 102, and output device 103.

The recording device 101 records the image data obtained by imaging forexample or from outside of the system, as content data, together withmetadata and so forth to an optical disc 110 which is a recording medium(arrow 121). For example, the recording device means a device whichimages a subject with an image sensor such as a CCD (Charge CoupledDevice), CMOS (Complementary Metal Oxide Semiconductor), or the like,and records onto a recording medium such as a memory card, magnetictape, or DVD or the like. For example, a digital still camera, videocamera, film scanner, and cellular phone with camera function or thelike correspond to the this recording device.

The playing device 102 read out the content data recorded in the opticaldisc 110 which is a recording medium (arrow 122), and supplies the readout content data to the output device 103 (arrow 123). The playingdevice 102 means a device having the function to play moving picturesrecorded on some type of recording medium. For example, a video tapeplayer, DVD player, Blu-ray disc player, and a digital still camera,video camera, and cellular phone or the like having a playing functioncorresponds thereto.

The output device 103 displays the image of the image data supplied formthe playing device 102. The output device 103 means a device having afunction to output a moving picture signal with some sort of method. Forexample, a television receiver, projector, printer, and a digital stillcamera, video camera, and cellular phone or the like having a monitorcorresponds thereto.

The information processing system 100 is a system to more properlyperform gamut conversion and restoration of image data, by coordinationbetween devices, in processing relating to image data such as in theabove.

The range of the gamut that can be displayed by the output device 103displaying a image is limited. Accordingly, in a normal case, gamutconversion processing which matches the gamut of the image data to theoutput device 103 is needed. For example, a portion of the image datagamut that is wider than the gamut of the output device 103 may resultin the occurrence of color phase shift. Conversely, a portion of theimage data gamut that is narrower than the gamut of the output device103 is not drawing out the capability of the output device 103 to themaximum. That is to say, matching the gamut of the image data to a gamutto which the output device can correspond is desirable.

The recording device 101 has a gamut conversion function to convert theimage data gamut as shown in FIG. 2. The playing device 102 and outputdevice 103 will not necessarily have these functions, so in order tosuppress the occurrence of color phase shift resulting from naturalclip, in the event of recording image data on the optical disc 110, therecording device 101 converts the image data gamut beforehand to apredetermined gamut having a limited range.

At this time, the recording device 101 can convert the image data gamutinto the gamut of when the image is output by the output device 103,i.e. the final gamut (main compression), or can convert into anothergamut (temporary compression). In the case of the temporary compression,the image data gamut is basically subjected to gamut conversion of thegamut of the output device 103 (main compression). Thus, the recordingdevice 101 adds metadata for the gamut conversion processing thereof(gamut metadata) to the image data and records this on the optical disc110.

Cases may be considered where the gamut of the output device 103 cannotbe identified at the point in time of recording the image data on theoptical disc 110. Accordingly, the image data gamut may result in beingnarrower than the gamut of the output device 103 from the gamutconversion by the recording device 101.

Now, the recording device 101 generates metadata (restoration metadata)for the restoration processing to restore the gamut to before the imagedata gamut conversion, adds this to the image data, and records on theoptical disc 110.

Note that gamut restoration is the processing to return a portion or allof the image data gamut to the state before the gamut conversion. Notethat in the case that the gamut before gamut conversion is infinitelywide, as with the image data obtained by imaging, “completely” restoringthe gamut is difficult, but at least partially restoring (the portionsactually usable) is possible.

Also, various devices are applicable to the playing device 102 andoutput device 103, as described above, and functions that the deviceshave are also varied. Accordingly, as shown in FIG. 2, the playingdevice 102 and output device 103 each have cases having, and cases nothaving, gamut conversion functions that subject the image data gamut tomain compression. Also, the playing device 102 and output device 103each have cases having, and cases not having, restoration processingfunction to restore the gamut to the gamut before image data gamutconversion.

Accordingly, when each of the playing device 102 and output device 103independently perform gamut conversion processing or restorationprocessing without planning, unnecessary processing can be generatedsuch as omission or duplication of processing, and this can lead tounnecessary image quality deterioration. Also, restoration processingand gamut conversion processing can be executed with an improper device.

Now, the playing device 102 and output device 103 perform bi-directionalcommunication (arrow 123), confirm mutual functions with each other,thereby controlling execution of gamut conversion processing andrestoration processing, selects with which device the processing thereofwill be executed, properly performs the processing with the selecteddevice, and suppresses execution of unnecessary processing andinefficient processing.

Also, for example, cases may be considered wherein bi-directionalcommunication thereof is not possible, such as cases where the device toserve as the communication partner does not have communicationfunctions, or in cases where communication environment is not arranged.With such cases also, the playing device 102 and output device 103perform execution control for gamut conversion processing andrestoration processing, respectively, so that content gamut conversioncan be more properly performed.

The recording device 101, playing device 102, and output device 103 maybe configured as mutually different devices, or the recording device 101and playing device 102 may be configured as one device (integrateddevice) that is separate from the output device 103. For example, ageneral video camera or digital still camera has a function serving asthe recording device 101 to image a subject and record the image datathereof on a recording medium, and a function serving as the playingdevice 102 to read out the image data recorded on the recording mediumand output to another device.

In such a case, we can consider the integrated device thereof to be arecording device 101 at the time of imaging operation mode, and aplaying device 102 at the time of image playing mode.

The optical disc 110 is an example of a recording medium (storagemedium) to record image data, and may be any sort if a recording mediumthat is writable (writing or rewriting). For example, there is a CD-R(Compact Disc-Recordable) and CD-RW (Compact Disc-Rewritable). Also, forexample, there is a DVD±R (Digital Versatile Disc±Recordable) or DVD±RW(Digital Versatile Disc±Rewritable). Further, for example, there is aDVD-RAM (Digital Versatile Disc Random Access Memory), BD-R (Blu-rayDisc Recordable), or BD-RE (Blu-ray Disc-Rewritable). If the recordingdevice 101 and playing device 102 are corresponding thereto, it goeswithout saying that an optical disc (recording medium) other than thesestandards may be used.

Also, instead of the optical disc 110, a flash memory, hard disk, ortape device may be used. Further, a flexible removable medium is notrequired and a built-in recording medium may be used. It goes withoutsaying that this recording medium may be configured as a separate devicefrom the recording device 101 and playing device 102, such as aperipheral device or server or the like.

Note that gamut conversion is processing to modify the gamut range.Accordingly, this includes cases of narrowing the gamut and cases ofwidening the gamut. For example, narrowing a certain portion of thegamut and widening another portion is also included. However, generally,gamut conversion mostly involves cases of gamut compression to narrowthe gamut. Accordingly, in the description below, description willbasically be given with a case of gamut compression as an example.However, the description below can basically be applied to gamutexpansion which widens the gamut.

FIG. 3 is a block diagram illustrating a primary configuration exampleof the recording device 101 in FIG. 2. As shown in FIG. 3, the recordingdevice 101 has an imaging unit 151, user specification accepting unit152, gamut conversion control unit 153, gamut conversion processing unit154, restoration metadata generating unit 155, and recording unit 156.

The imaging unit 151 images a subject based on user instructionsreceived by the user instruction accepting unit 152, generates the imagedata thereof, and supplies this to the gamut conversion control unit153. The user specification accepting unit 152 has a user interface suchas switches and buttons for example, and via these accepts specifying(instructing) operations from a user. The user specification acceptingunit 152 supplies the input user specifications to the imaging unit 151and gamut conversion control unit 153.

The gamut conversion control unit 153 selects an optimal method forgamut conversion, based on the user specifications and various types ofsetting values and so forth. The gamut conversion processing unit 154converts the image data gamut and generates gamut metadata indicatingthe gamut after conversion, based on the controls of the gamutconversion control unit 153 thereof (with the selected method).

In the case of being controlled by the gamut conversion control unit 153to generate the restoration metadata, the restoration metadatagenerating unit 155 obtains the image data subjected to gamut conversionand the gamut metadata from the gamut conversion processing unit 154,then based on the image data thereof, generates the restoration metadatafor restoring the gamut before gamut conversion. The restorationmetadata generating unit 155 supplies the image data, gamut metadata,and restoration metadata to the recording unit 156.

In the case of being controlled by the gamut conversion control unit 153so as to not generate the restoration metadata, the gamut conversionprocessing unit 154 supplies the image data and gamut metadata to therecording unit 156 without going via the restoration metadata generatingunit 155.

The recording unit 156 shows a writing function of a drive on which theoptical disc 110 is mounted, for example. The recording unit 156 recordsthe image data and gamut metadata supplied from the gamut conversionprocessing unit 154, or image data, gamut data, and restoration metadatasupplied from the restoration metadata generating unit 155, as contentto the optical disc 110 mounted on the drive.

FIG. 4 is a block diagram showing a primary configuration example of theplaying device 102 in FIG. 2.

As shown in FIG. 4, the playing device 102 has a playing unit 161,restoration gamut conversion control unit 162, restoration processingunit 163, gamut conversion processing unit 164, and communication unit165.

The playing unit 161 shows a readout function of the drive to which theoptical disc 110 is mounted, for example. The playing unit 161 reads outthe content from the optical disc 110 mounted on the drive (e.g., imagedata, gamut metadata, and restoration metadata) and supplies this to therestoration gamut conversion control unit 162.

The restoration gamut conversion control unit 162 performs processingcontrol relating to restoration and gamut conversion as to the imagedata read out by the playing unit 161 (and the gamut metadata andrestoration metadata). For example, the restoration gamut conversioncontrol unit 162 selects whether or not the read out image data will besubjected to performing restoration or gamut conversion or not, and inthe case of performing, whether to perform this with this playing deviceor with an output device 103 at a later stage, and so forth.

The restoration gamut conversion control unit 162 has a restorationconversion state confirming unit 171, an information exchange unit 172,and a determining unit 173. The restoration conversion state confirmingunit 171 performs confirmation of the gamut conversion state of theimage data read out from the optical disc 110 and whether or not thereis any restoration metadata and the like. For example, the restorationconversion state confirming unit 171 references the gamut of the imagedata read out from the optical disc 110, and confirms whether this isimage data that has been subject to temporary compression (temporarycompression data) or is image data that has been subject to maincompression (main compression data). Further, the restoration conversionstate confirming unit 171 references whether or not there is anyrestoration metadata, and also confirms whether restoration is possible.

The information exchange unit 172 communicates with the output device103 via the communication unit 165, and performs an exchange ofinformation, such as the existence of a restoration processing functionand gamut conversion function. The determining unit 173 determineswhether or not to perform restoration processing with this playingdevice 102, based on the information obtained from the restorationconversion state confirming unit 171 and information exchange unit 172.Similarly, the determining unit 173 determines whether or not to performgamut conversion processing with this playing device 102, based on theinformation obtained from the restoration conversion state confirmingunit 171 and information exchange unit 172.

The restoration processing unit 163 is controlled by the restorationgamut conversion control unit 162, and performs restoration processingof the gamut of the temporary compression data read out from the opticaldisc 110. The restoration processing unit 163 supplies the image datasubjected to restoration processing to the gamut conversion processingunit 164.

The gamut conversion processing unit 164 is controlled by therestoration gamut conversion control unit 162, and performs gamutconversion (main compression) of the temporary compression data read outfrom the optical disc 110 from the playing unit 161 to the gamut of theoutput device 103. Also, the gamut conversion processing unit 164 iscontrolled by the restoration gamut conversion control unit 162, andperforms gamut conversion (main compression) of the image data of whichthe gamut before temporary compression has been restored with therestoration processing unit 163, to the gamut of the output device 103.The gamut conversion processing unit 164 supplies the image datasubjected to main compression (main compression data) to thecommunication unit 165. At this time, the gamut conversion processingunit 164 supplies the gamut metadata and restoration metadata of theimage data, together with the main compression data as needed, to thecommunication unit 165.

Also, in the case that the image data read out from the optical disc 110is main compression data, the determining unit 173 supplies this to thecommunication unit 165 without performing restoration processing orgamut conversion processing. Note that even in the case of performingrestoration processing and gamut conversion processing with the outputdevice 103, the determining unit 173 supplies the image data read outfrom the optical disc 110 and the metadata thereof to the communicationunit 165.

Note that the restoration processing unit 163 and gamut conversionprocessing unit 164 can each be omitted. In this case, the playingdevice 102 cannot perform the restoration processing and gamutconversion processing that corresponds to the omitted processing unit,so the determining unit 173 performs control so as to omit theprocessing thereof, as appropriate.

The communication unit 165 performs communication with the output device103, and exchanges information relating to restoration processing andgamut conversion, and supplies image data (and gamut metadata andrestoration metadata) to the output device 103.

FIG. 5 is a block diagram showing a primary configuration example of theoutput device 103 in FIG. 2.

As shown in FIG. 5, the output device 103 has a communication unit 181,information providing unit 182, restoration processing unit 183, gamutconversion processing unit 184, and output unit 185. The communicationunit 181 performs communication with the playing device 102, andexchanges information relating to gamut conversion processing andrestoration processing, and obtains image data (and gamut metadata andrestoration metadata) supplied from the playing device 102.

Also, in accordance with control by the playing device 102, thecommunication 181 supplies the obtained image data and so forth to oneof the restoration processing unit 183, gamut conversion processing unit184, and output unit 185. For example, in the case of performingrestoration processing with the output device 103, the communicationunit 181 supplies the image data and so forth to the restorationprocessing unit 183. Also, for example, in the case that restorationprocessing is not performed with the output device 103 but gamutconversion processing is performed, the communication unit 181 suppliesthe image data and so forth to the gamut conversion processing unit 184.Further, for example, in the case that neither restoration processingnor gamut conversion processing is performed with the output device 103,the communication unit 181 supplies the image data to the output unit185.

The information providing unit 182 has information relating torestoration processing and gamut conversion, to be provided to theplaying device 102 via the communication unit 181, and supplies theinformation thereof to the communication unit 181 as appropriate.

The restoration processing unit 183 performs restoration processing ofthe gamut of the temporary compression data supplied via thecommunication unit 181. The restoration processing unit 183 supplies theimage data subjected to restoration processing to the gamut conversionprocessing unit 184.

The gamut conversion processing unit 184 performs gamut conversionprocessing (main compression) that convert the gamut of the temporarycompression data supplied via the communication unit 181 or the imagedata which is restored to the gamut before gamut conversion with therestoration processing by the restoration processing unit 183, into agamut that the output unit 185 can express. The gamut conversionprocessing unit 184 supplies the main compression data to the outputunit 185.

The output unit 185 has monitor such as an LCD (Liquid Crystal Display),PDP (Plasma Display Panel), or organic EL display (OELD (OrganicElectroluminescence Display)) and printer and so forth, and displays andprints (i.e., outputs) the images of the image data.

Next, the flow of processing executed with each device will bedescribed.

[Flow of Processing of Recording Device]

First, the flow of processing executed with the recording device 101will be described. The recording device 101 executes recording controlprocessing in the event of recording the image data obtained by imaginga subject or the like onto the optical disc 110, and performs gamutconversion of the image data. An example of flow of the recordingcontrol processing will be described with reference to the flowchart inFIG. 6.

Upon the recording control processing starting, in step S101 the gamutconversion control unit 153 determines whether or not a standard targetgamut in the information processing system 100 has been specified, basedon user specification accepted by the user specification accepting unit152, the user specification accepted beforehand and stored, varioustypes of setting values that have been updated by the userspecifications thereof, or other various types of setting values or thelike. The standard target gamut is a gamut that has been predefined as astandard value of the target gamut which is a final gamut of the imagedata in the information processing system 100. Generally, a relativelynarrow gamut such as sRGB is applied to this standard target gamut.

The gamut conversion control unit 153 determines whether or not thestandard target gamut has been specified as the gamut after conversion.In the case determination is made that the standard target gamut hasbeen specified, the flow advances to step S102. In step S102, the gamutconversion processing unit 154 performs main compression as to the imagedata gamut with the standard target gamut.

Now, main compression is to convert the gamut of the image data into thegamut at the time of image output, i.e., the final gamut. For example,the image gamut at the time of imaging is sufficiently large and thesame as being infinite. However, in this case, the colors expressed withthe playing device 102 and output device 103 may fail, so gamutconversion of the image data is performed. At this time, converting to agamut in the event that the image is output with the output device 103is called main compression. In a normal case, the target gamut for maincompression is the standard target gamut. Causing the gamut to beunnecessarily narrow is meaningless, so generally the gamut is thenarrowest target gamut at the time of main compression.

In step S103, the storage unit 156 records the main compression dataobtained by main compression with the gamut conversion processing unit154, together with the gamut metadata thereof (standard target gamutmetadata), onto the optical disc 110 and ends the recording controlprocessing.

Also, in the case determination is made in step S101 that the standardtarget gamut has not been specified, the processing advances to stepS104. In step S104, the gamut conversion processing unit 154 iscontrolled by the gamut conversion control unit 153 and performstemporary compression with the temporary target gamut specified by theuser specifications accepted with the user specification accepting unit152.

Temporary compression is compression other than main compression. Thereis no limit to the target gamut in this temporary compression. However,in many cases, a gamut that is wider than the target gamut at time ofmain compression is used for the target gamut. At the point in time thatthe image data is recorded onto the optical disc 110, from what sort ofoutput device 103 the image data will be output is unclear. Thus, withthe gamut conversion processing unit 154, for safety purposes (so thatproblems do not occur at later stages), the image data gamut isconverted to a temporary target gamut defined based on userspecifications, and the image data after the gamut conversion thereof isrecorded onto the optical disc 110. Such gamut conversion is calledtemporary compression.

Upon temporary compressing ending, the gamut conversion control unit 153determines in step S105 whether or not predetermined restorationmetadata adding conditions hold. In the case determination is made thatthe restoration metadata adding conditions are satisfied, the processingis advanced to step S106.

In step S106, the restoration metadata generating unit 155 generatesrestoration metadata to be referenced in the event of restorationprocessing. In step S107, the recording unit 156 records the temporarycompression data obtained by temporary compression, together with thegamut metadata (temporary target gamut metadata) and the restorationmetadata generated by the processing in step S106, onto the optical disc110, and ends the recording control processing.

Also, in step S105, in the case determination is made that therestoration metadata adding conditions are not satisfied, the flow isadvanced to step S108. In step S108, the recording unit 156 records thetemporary compression data obtained by the temporary compression,together with the gamut metadata (temporary target gamut metadata) ontothe optical disc 110, and ends the recording control processing. That isto say, in this case, the restoration metadata is not added.

With the above recording control processing, the restoration metadataadding conditions in step S105 are conditions to be satisfied in orderto add the restoration metadata. The content of these conditions isbasically optional.

For example, a restoration metadata adding condition may be that theuser specifies the attaching of the restoration metadata. That is tosay, in this case, whether or not the restoration metadata is added isdetermined by user specification.

In the case determination is made in step S105 that the user hasspecified the attaching of the restoration metadata, the flow isadvanced to step S106. That is to say, restoration metadata isgenerated, and attached to the image data and recorded. The playingdevice 102 or output device 103 can execute the restoration processingusing the restoration metadata thereof. Conversely, in the casedetermination is made in step S105 that the user has not specified theattaching of the restoration metadata, the flow is advanced to stepS108. That is to say, restoration metadata is not generated.Accordingly, the playing device 102 and output device 103 cannot executerestoration processing.

Also, for example, a restoration metadata adding condition may be thatthe word length of the compression data to be recorded is at least apredetermined length (e.g., 9-bit) (is a high tone image).

Generally the word length of image data is 8-bit or less, but some imagedata exists for high tone images wherein the word length is 9-bit orgreater.

In the case that the word length of the image data is smaller than9-bit, even if the restoration metadata is attached and restorationperformed, there is a great possibility that tone jumping will occur inthe image data restored with insufficient precision of image data, wheretone continuity is lost. To counter this, methods to reduce the tonejumping by using an error dispersion method in the vicinity where thetone jumping occurs may be considered even when precision isinsufficient, but processing becomes complex so this is often not used.Generally, restoration processing is often used in cases only wheresimple data decompression is performed for each pixel. Accordingly, evenif 8-bit data is restored, usable restoration data may not be obtained.

Now, restoration metadata is generated so that restoration processingcan be executed only in the case of a high-tone image that is higherthan a predetermined tone (e.g. the word length is 9-bit or greater),and added to the image data.

Note that a case may be considered wherein, in the event of performingimage processing, for the image processing thereof, a low-tone imagethat is lower than a predetermined tone is processed to have a highertone, and returned to the original tone after the image processing. Forexample, there is a method wherein the tone of the image data having aword length of 8-bit is increased to 9-bit and signal processing isperformed, then returned to 8-bit. More specifically, for example, therecording device 101 recording onto the optical disc 110 afterincreasing the tone of a low tone image and after gamut conversion, andthe playing device 102 reading out the high tone image thereof andperforming restoration processing and gamut conversion processing, thendecreasing the tone and outputting this to the output device 103, mayalso be considered.

Thus, even if the image is originally low tone, if the high tone at thetime of gamut restoration processing, the gamut can be restored withsufficient precision. Accordingly, images with tone thus increased areincluded in the above-mentioned high tone images.

In the case determination is made in step S105 that the word length ofthe image data is 9-bit or greater (is a high tone image), the flow isadvanced to step S106. That is to say, restoration metadata isgenerated, attached to the image data, and recorded. The playing device102 or output device 103 can execute the restoration processing usingthe restoration metadata thereof. Conversely, in the case determinationis made in step S105 that the word length of the image data is 8-bit orless (not a high tone image), the flow is advanced to step S108. That isto say, restoration metadata is not generated. Accordingly, the playingdevice 102 and output device 103 cannot execute the restorationprocessing.

Note that the bit length to be set as a threshold of whether high toneor not is arbitrary. For example, this may be 10-bit or 12-bit and soforth, or may be 6-bit and so forth. Also an arrangement may be madewherein the user can arbitrary set this.

Also, cases may be considered wherein the word length of the image datais determined based on other conditions such as the format or the imagedata and so forth. For example, in the case of a bit map (BMP) format ora JPEG (Joint Photographic Experts Group) format, the word length for astill image is 8-bit.

Accordingly, determination may be made, at the point in time that theimage data is generated with the imaging unit 151, as to whether or notrestoration metadata will be added. In such a case, the processing instep S105 is skipped, and either one of the various processing in stepsS106 and step S107, or the processing in step S108, is executed.

As shown above, when the gamut conversion control unit 153 determinesthe target gamut specified by the user, the gamut conversion processingunit 154 converts the image data to the specified gamut thereof, andfurther, in the case of temporary compression, predetermined restorationmetadata adding conditions are satisfied, the restoration metadatagenerating unit 155 generates and attaches the restoration metadata.

By performing recording control processing in this way, the gamutconversion control unit 153 can control whether or not to enable theplaying device 102 or output device 103 to execute restorationprocessing. That is to say, the recording device 101 can cause theplaying device 102 or output device to perform control of restorationprocessing and gamut conversion processing with consideration forsituations at the time of recording such as user specification and imagedata word length.

Note that in the above, description is made such that determination ismade in step S101 as to whether or not a standard target gamut has beenspecified, but cases wherein a gamut to be a target (target) is definedbeforehand may also be considered.

For example, in the case that the image data is data of a still image,and the format thereof is bitmap format (BMP) or PNG format, the sRGBgamut becomes the target gamut. Also, for example, in the case that theimage data is moving image data, and the image thereof is SD(Standard-Definition), the BT601 gamut having the same width as the sRGBgamut becomes the target gamut, and in the case that the image is HD(High-Definition), the BT709 gamut having the same width as the sRGBgamut becomes the target gamut.

In the case that the format of the image data is defined beforehand asthese formats, a gamut corresponding to the format is selected as thetarget gamut. That is to say, the gamut thereof (sRGB gamut, BT601gamut, BT709 gamut) are set as the standard target gamut, and maincompression is performed. That is to say, in this case, the determiningprocessing in step S101 is skipped, and the processing in step S102 andstep S103 are performed.

Also, a gamut serving as the target (goal) may be defined by the imagingmode, for example. For example, in the case that the mode at time ofimaging by the imaging unit 151 is a standard (standard) mode, thetarget gamut may be set as the sRGB gamut. In this case, at the point intime that the user selects standard mode at time of imaging, sRGB gamutis selected as the target gamut. That is to say, this sRGB gamut is setas the standard target gamut, and main compression is performed. That isto say, in this case, the determining processing in step S101 isskipped, and the processing in step S102 and step S103 are performed.

[Flow of Processing of Playing Device]

Next, processing to be executed with the playing device 102 will bedescribed. The playing device 102 executes playing determiningprocessing in the event of reading out content data such as image dataor the like from the optical disc 110. An example of flow of the playingdetermining processing thereof will be described with reference to theflowchart in FIG. 7.

Upon the playing determining processing starting, in step S121 theplaying unit 161 reads out the image data to be played, and the metadatathereof, from the optical disc 110. In step S122 the restorationconversion state confirming unit 171 confirms whether the image data tobe played (playing data) has been temporarily compression (temporarycompression data) or has been main-compressed (main compression data),based on various types of information such as image data headerinformation, flag information, gamut metadata, or restoration metadataor the like.

In step S123, the various processing units of the information exchangeunit 172 and determining unit 173, and the restoration processing unit163 through the communication unit 165 execute playing controlprocessing to perform restoration processing and gamut conversionprocessing in accordance with the gamut conversion state and the like.

Upon the playing control processing having ended, the playingdetermining processing is ended.

Next, the playing control processing and so forth will be described.First, a case will be described wherein the image data read out from theoptical disc 110 is temporary compression data, and restoration metadataand gamut metadata are both attached thereto, i.e., in the case that theprocessing in step S108 is performed in the recording control processingdescribed with reference to the flowchart in FIG. 6.

An example of flow of the playing control processing will be describedwith reference to FIG. 8.

Upon the playing control processing having started, in step S141 theinformation exchange unit 172 confirms the communication with the outputdevice 103, and in step 142 determines whether or not the communicationwith the output device 103 is possible. In the case that communicationis possible, the flow is advanced to step S143.

In step S143, the determining unit 173 determines whether or notrestoration processing can be executed with the playing device 102,i.e., whether or not the playing device 102 has a restoration processingunit 163 and gamut conversion processing unit 164. In the casedetermination is made that the playing device 102 can executerestoration processing, the flow is advanced to step S144.

In step S144, the information exchange unit 172 performs an inquiryabout the restoration processing function to the output device 103,confirms the restoration processing capability of the output device 103,and in step S145 determines whether or not the restoration processingcan be executed with the output device 103. In the case that the outputdevice 103 does not have a restoration processing unit 183, and isdetermined to be unable to execute the restoration processing with theoutput device 103, the flow is advanced to step S146.

In step S146, the information exchange unit 172 accesses the outputdevice 103, and obtains the gamut information of the output device 103.In step S147 the restoration processing unit 163 is controlled by therestoration gamut conversion control unit 162, and using the gamutinformation of the output device 103 obtained by the processing in stepS146, compares the gamut of the image data read out from the opticaldisc 110 (image data gamut) and the gamut of the output device 103(output gamut).

In step S148 the restoration processing unit 163 determines whether ornot the output gamut is “completely” small as to the image data gamut.In the case that portions outside the image data gamut are included inthe output gamut, and the output gamut is not “completely” small as tothe image data gamut, the flow is advanced to step S149.

In step S149, the restoration processing unit 163 performs restorationprocessing using the restoration metadata attached to the image data,and restores the gamut to before gamut conversion of the image data.

That is to say, in this case, restoration processing cannot be performedwith the output device 103 (the output device does not have restorationprocessing functionality), and restoration processing is necessary(portions outside the image data gamut are included in the outputgamut), so the playing device 102 itself performs restorationprocessing.

Upon the restoration processing having ended, in step S150 theinformation exchange unit 172 performs confirmation of the deviceconditions for gamut conversion processing with the output device 103,via the communication unit 165. Based on the confirmation resultsthereof, the determining unit 173 determines in step S151 whether or notthe output device 103 satisfies the device conditions.

The device condition for the gamut conversion processing is a conditionin order to select a more favorable device for executing the gamutconversion processing, and the content thereof is optional as long asthis is the purpose thereof. For example, the device condition may bethat the manufacturing source of the playing device 102 and outputdevice 103 are the same. Generally, in the case that the manufacturingsources match, the gamut of the output device 103 is often known by theplaying device 102. Also, in many cases the algorithms and so forth ofthe restoration processing and gamut conversion processing mutuallycorrespond. Accordingly, in the case that the manufacturing source ofthe output device 103 matches the manufacturing source of the playingdevice 102, the temporary compression data can be handed over to theoutput device 103 without change, and this is relatively safe.

Also, a device condition may be that the version of the gamut conversionalgorithm is higher for the output device (perform gamut conversionprocessing with a newer algorithm than the playing device 102). In thecase that the gamut conversion algorithm version is higher for theoutput device, the gamut conversion processing is controlled so as to beperformed with the output device 103.

It goes without saying that an arrangement may be used other than these.For example, the gamut conversion algorithm can subject the image datahaving a predetermined data length (e.g., 8-bit) to gamut conversion.Also, an arrangement may be made wherein a longer data length can beprocessed.

In the case determination is made that the device condition for thegamut conversion processing as described above does not hold, the flowis advanced to step S152. In step S152, the gamut conversion processingunit 164 performs main compression using the gamut information of theoutput device 103. In step S153 the communication unit 165 supplies themain compression data generated in step S152 to the output device 103,and ends the playing control processing.

Also, in the case determination is made in step S151 that the devicecondition holds for the gamut conversion processing, the flow isadvanced to step S154. In step S154, the communication unit 165 suppliesthe image data, the gamut of which is restored to before gamutconversion, together with the gamut metadata to the output device 103,and ends the playing control processing.

That is to say, in this case, it is desirable for the gamut conversionprocessing to be executed with the output device 103, so the playingdevice 102 causes the output device 103 to perform gamut conversionprocessing.

Also, in the case determination is made in step S148 that the gamut ofthe output device 103 is completely small, the flow is advanced to stepS152.

That is to say, in this case, restoration processing is unnecessary, sothe processing in step S149 and so forth are skipped, and the flow isadvanced to step S152. That is to say, main compression is performedwith the playing device 102.

In the case determination is made in step S145 that the output device103 can execute the restoration processing, the flow is advanced to stepS155. In step S155 the information exchange unit 172 exchangesinformation with the output device 103, and confirms the deviceconditions for the restoration processing as to the output device 103.Based on the confirmation results thereof, the determining unit 173determines in step S156 whether or not the output device 103 satisfiesthe device conditions.

The device condition for the restoration processing is a condition inorder to select a more favorable device for executing the restorationprocessing, and the content thereof is optional as long as this is thepurpose thereof. For example, the device condition may be that themanufacturing source of the playing device 102 and output device 103 arethe same. Generally, in the case that the manufacturing sources match,this is relatively safe, so the restoration processing is controlled tobe performed with the output device 103.

Also, a device condition may be that the version of the restorationprocessing algorithm is higher for the output device (performrestoration processing with a newer algorithm than the playing device102). In the case that the restoration algorithm version is higher forthe output device 103, the restoration processing is controlled so as tobe performed with the output device 103.

It goes without saying that an arrangement may be made other than these.For example, the restoration algorithm can restore the gamut of theimage data having a predetermined data length (e.g., 8-bit). Also, anarrangement may be made wherein a longer data length can be processed.

In the case determination is made in step S156 that the device conditionfor the restoration processing such as described above does not hold,the flow is returned to step S146. That is to say, in this case, controlis performed so that when restoration processing is necessary, this isexecuted with the playing device 102.

Also, in the case determination is made in step S156 that the devicecondition for the restoration processing holds, the flow is advanced tostep S157.

In step S157 the determining unit 173 supplies the temporary compressiondata together with the gamut metadata and restoration metadata to theoutput device 103, and ends the playing control processing. In otherwords, in this case, control is performed so that when restorationprocessing is necessary, this is executed with the output device 103.

Also, in the case determination is made in step S143 that restorationprocessing is impossible with the playing device 102, the flow isadvanced to step S158. In step S158, the information exchange unit 172confirms the restoration processing capability of the output device 103,and the determining unit 173 determines whether or not the output device103 can execute the restoration processing, based on the confirmationresults thereof.

In the case determination is made that the output device 103 can executethe restoration processing, the flow is returned to step S157. That isto say, in this case, execution of the restoration processing with theplaying device 102 is impossible, and execution of the restorationprocessing with the output device 103 is possible, whereby control isperformed so that the restoration processing is performed with theoutput device 103.

Also, in the case determination is made in step S159 that execution ofthe restoration processing with the output device 103 is impossible, theflow is advanced to step S160.

In step S160, the various parts of the playing device 102 executes thegamut conversion control processing to control processing relating togamut conversion. That is to say, in this case, restoration processingcannot be performed with the playing device 102 and with the outputdevice 103. Thus, gamut conversion control processing is executed sothat the various units of the playing device 102 can perform at leastthe gamut conversion processing. Details of the gamut conversion controlprocessing will be described later.

Upon the gamut conversion processing having ended, the playing controlprocessing is ended.

Also, in the case determination is made in step S142 that bi-directionalcommunication with the output device 103 cannot be performed, the flowis advanced to step S161. In step S161, the restoration gamut conversioncontrol unit 162 causes the various units to execute error processing,and ends the playing control processing. That is to say, sincebi-directional communication between the playing device and outputdevice cannot be performed (necessary information exchange cannot bemade for the restoration processing and gamut conversion), the output ofimage data is stopped.

An example of flow of the gamut conversion control processing executedwith in step S160 in FIG. 8 will be described with reference to theflowchart in FIG. 9.

Upon the gamut conversion control processing starting, in step S181 thedetermining unit 173 determines whether or not gamut conversion ispossible with the playing device 102, i.e., whether or not the playingdevice 102 has a gamut conversion processing unit 164. In the casedetermination is made that gamut conversion is possible, the flow isadvanced to step S182.

In step S182, the information exchange unit 172 inquires to the outputdevice 103, and confirms the gamut conversion capability of the outputdevice 103. Based on the confirmation results thereof, the determiningunit 173 determines in step S183 whether or not gamut conversion ispossible with the output device 103. In the case determination is madethat gamut conversion is impossible, the flow is advanced to step S184.

In step S184, the gamut conversion processing unit 164 is controlled bythe restoration gamut conversion control unit 162 to obtain gamutinformation of the output device 103. In step S185, the gamut conversionprocessing unit 164 performs main compression. In step S186, thecommunication unit 165 is controlled by the restoration gamut conversioncontrol unit 162, and provides the main compression data obtained withthe processing in step S185 to the output device 103. At this time, thecommunication unit 165 supplies the standard target gamut, together withthe main compression data, to the output device 103 as needed.

Also, in the case determination is made in step S183 that gamutconversion can be executed with the output device 103, the flow isadvanced to step S187. In step S187, the information exchange unit 172exchanges information with the output device 103, and confirms thedevice conditions for the gamut conversion processing. The deviceconditions are similar to the device conditions in the case of step S151in FIG. 8, so the description thereof will be omitted. In step S188 thedetermining unit 173 determines whether or not the device conditionshold. In the case determination is made that the device conditions donot hold for the gamut conversion processing, the flow is returned tostep S184.

That is to say, in this case, gamut conversion can be performed withboth the playing device 102 and the output device 103, but performinggamut conversion with the playing device 102 is more desirable, socontrol is performed so that gamut conversion is performed with theplaying device 102.

Also, in the case determination is made in step S188 that the deviceconditions for the gamut conversion processing holds, the flow isadvanced to step S189. In step S189, the communication unit 165 suppliesthe temporary compression data, together with the gamut metadata, to theoutput device 103. That is to say, in this case, gamut conversion can beperformed with both the playing device 102 and the output device 103,but performing gamut conversion with the output device 103 is moredesirable, so control is performed so that gamut conversion is performedwith the output device 103.

Upon the image data having been supplied to the output device 103, thegamut conversion control processing is ended.

Also, in the case determination is made in step S181 that execution ofgamut conversion by the playing device 102 is impossible, the flow isadvanced to step S190. In step S109 the information exchange unit 172confirms the gamut conversion capability of the output device 103. Instep S191 the determining unit 173 determines whether or not gamutconversion can be executed with the output device 103, based on theconfirmation results thereof. In the case determination is made thatgamut conversion is possible with the output device 103, the flow isadvanced to step S189. In this case, control is performed so that theoutput device 103 does not perform main compression. In the casedetermination is made that the output device also cannot perform gamutconversion, the flow is advanced to step S192.

In step S192 the restoration gamut conversion control unit 162 causesthe various units to execute error processing, and ends the gamutconversion control processing. That is to say, in this case, neither theplaying device 102 nor the output device 103 can perform gamutconversion, so the output of the image data is stopped.

The playing device 102 controls restoration processing and gamutconversion processing by executing processing such as described above.

[Flow of Processing of Output Device]

Next, processing to be executed with the output device 103 will bedescribed. The output device 103 executes output control processing asto the control processing of the playing device 102 described above, andresponds to requests from the playing device 102. An example of the flowof output control processing thereof will be described with reference tothe flowchart in FIG. 10.

Upon output control processing starting, in step S211 the communicationunit 181 confirms communication with the playing device 102, and in stepS212 determines whether or not bi-directional communication is possible.In the case determination is made that bi-directional communication ispossible, the flow is advanced to step S213.

In step S213, the various units of the output device 103 link with theplaying device 102, and executes restoration conversion controlprocessing which appropriately controls the execution of the restorationprocessing and gamut conversion processing. Details of the restorationconversion control processing will be described later.

In step S214, the information providing unit 182 determines whether ornot the output control processing has ended. Until determination is madein step S214 that output control processing has been ended, therestoration conversion control processing in step S213 is repeatedlyexecuted.

In the case determination is made in step S214 that output controlprocessing is to be ended, the flow is advanced to step S215. In stepS215, the output unit 185 outputs the main compression data created withthe restoration conversion control processing, and ends the outputcontrol processing.

Also, as described above, in the case bi-directional communication isimpossible, the output of image data is stopped, so in step S212, in thecase determination is made that bi-directional communication isimpossible, the output control processing is ended.

Next, a detailed example of the flow of restoration conversion controlprocessing executed in step S213 will be described with reference to theflowchart in FIG. 11.

Upon the restoration conversion control processing starting, in stepS231 the information providing unit 182 determines whether or notrestoration processing capability is confirmed from the playing device102. In the case determination is made that the restoration processingcapability has been confirmed via the communication unit 181, the flowis advanced to step S232. In step S232, the information providing unit182 notifies the playing device 102 of the restoration processingcapability of the output device 103, via the communication unit 181.

Upon notification ending, the flow is advanced to step S233. Also, instep S231, in the case determination is made that restoration processingcapability is not confirmed, the processing in step S232 is skipped, andthe flow is advanced to step S233.

In step S233, the information providing unit 182 determines whether ornot gamut conversion capability has been confirmed from the playingdevice 102. In the case determination is made that gamut conversioncapability has been confirmed via the communication unit 181, the flowis advanced to step S234. In step S234 the information providing unit182 notifies the playing device 102 of the gamut conversion capabilityof the output device 103, via the communication unit 181.

Upon notification ending, the flow is advanced to step S235. Also, inthe case determination is made in step S233 that gamut conversioncapability is not confirmed, the processing in step S234 is skipped, andthe flow is advanced to step S235.

In step S235, the information providing unit 182 determines whether ornot the information (gamut information) showing the gamut of the outputdevice 103 has been requested from the playing device 102. In the casedetermination is made that the gamut information has been requested, theflow is advanced to step S236. In step S236, the information providingunit 182 supplies the gamut information showing the gamut of the outputdevice 103 to the playing device 102, via the communication unit 181.

Upon gamut information being supplied, the flow is advanced to stepS237. Also, in the case determination is made in step S235 that gamutinformation has not been requested, the information providing unit 182skips the processing in step S236 and advances to step S237.

In step S237, the communication unit 181 determines whether or not maincompression data has been supplied from the playing device 102. In thecase determination is made that main compression data has been supplied,the flow is advanced to step S238. In step S238, the communication unit181 obtains the main compression data thereof, and supplies this to theoutput unit 185.

Upon main compression data having been supplied to the output unit 185,the flow is advanced to step S239. Also, in the case determination ismade in step S237 that main compression data has not been supplied, theprocessing in step S238 is skipped, and the flow is advanced to stepS239.

In step S239 the information providing unit 182 determines whether ornot the device conditions for the restoration processing has beenconfirmed from the playing device 102. An example of the deviceconditions for the restoration processing is as described with referenceto FIG. 8.

In the case determination is made that device conditions for therestoration processing have been confirmed via the communication unit181, the flow is advanced to step S240. In step S240, the informationproviding unit 182 notifies the confirmation results of the deviceconditions for restoration processing of the output device 103, via thecommunication unit 181.

Upon ending notification, the flow is advanced to step S241. Also, inthe case determination is made in step S239 that device conditions forthe restoration processing have not been confirmed, the processing instep S240 is skipped, and the flow is advanced to step S241.

In step S241, the information providing unit 182 determines whether ornot the device conditions for the gamut conversion processing has beenconfirmed by the playing device. The example of device conditions forthe gamut conversion processing is as described with reference to FIG.8.

In the case determination is made that device conditions for the gamutconversion processing have been confirmed via the communication unit181, the flow is advanced to step S242. In step S242, the informationproviding unit 182 notifies the confirmation results of the deviceconditions for the gamut conversion processing of the output device 103,via the communication unit 181.

Upon notification ending, the flow is advanced to step S243. In the casedetermination is made in step S241 that device conditions for the gamutconversion processing have not been confirmed, the processing in stepS242 is skipped, and the flow is advanced to step S243.

In step S243, the communication unit 181 determines whether or not thetemporary compression data has been supplied together with the gamutmetadata thereof from the playing device 102. In the case determinationis made that the temporary compression data has been supplied togetherwith the gamut metadata thereof, the flow is advanced to step S244. Instep S244 the communication unit 181 obtains the temporary compressiondata and gamut metadata supplied from the playing device 102. In stepS245 the gamut conversion processing unit 184 uses the gamut informationof the output device 103 and the gamut metadata of the temporarycompression data to perform main compression of the temporarycompression data.

Upon the main compression ending, the flow is advanced to step S246.Also, in the case determination is made in step S243 that the temporarycompression data has not been supplied together with the gamut metadatathereof, the processing in step S244 and step S245 are skipped, and theflow is advanced to step S246.

In step S246, the communication unit 181 determines whether or not thetemporary compression data has been supplied together with the gamutmetadata thereof and restoration metadata from the playing device 102.In the case determination is made that the temporary compression data,gamut metadata, and restoration metadata have been supplied from theplaying device 102, the flow is advanced to step S247.

In step S247, the communication unit 181 obtains the temporarycompression data, gamut metadata, and restoration metadata from theplaying device 102. In step S248, the communication unit 181 uses thegamut information of the output device 103 itself and the gamut metadataof the temporary compression data, and compares the gamut of thetemporary compression data (image data gamut) and the gamut of theoutput device 103 (output gamut). In step S249, as a result of thecomparison thereof, the communication unit 181 determines whether or notthe gamut of the output device 103 (output gamut) is “completely”smaller than the gamut of the temporary compression data (image datagamut).

Now, the gamut being “completely” small means that the output gamut forall of the hues is included within the image data gamut. In the casedetermination is made in step S249 that the output gamut includesregions outside of the image data gamut, and is not “completely” small,the flow is advanced to step S250. In step S250, the restorationprocessing unit 183 performs restoration processing, using therestoration metadata as to the temporary compression data.

Upon restoration processing ending, the flow is advanced to step S251.Also, in the case determination is made in step S249 that the outputgamut is “completely” smaller than the image data gamut, the processingin step S250 is skipped, and the flow is advanced to step S251.

In step S251, the gamut conversion processing unit 184 performs maincompression using gamut metadata as to the image data (temporarycompression data or image data subjected to restoration processing), andsupplies the obtained main compression data to the output unit 185. Uponthe processing in step S251 ending, the restoration conversion controlprocessing is ended, the flow is returned to step S213 in FIG. 10, andthe processing in step S213 and thereafter is performed.

Also, in step S246 in FIG. 11, in the case determination is made thatthe temporary compression data, gamut metadata, and restoration metadataare not supplied, the various processing in step S247 through step S251are skipped, the restoration conversion control processing is ended, theflow is returned to step S213 in FIG. 10, and the processing in stepS214 and thereafter is performed.

As described above, by performing control of the restoration processingand gamut conversion processing according to various conditions, even ina case of handling content with multiple devices, the playing device 102and output device 103 can suppress unnecessary execution of restorationprocessing and gamut conversion processing, and execution of restorationprocessing and gamut conversion processing by inefficient methods, andcan perform restoration and gamut conversion of content more reliablyand properly.

2. Second Embodiment Device Configuration

Note that according to the first embodiment, for control of therestoration processing and gamut conversion processing with the playingdevice 102 and output device 103, description is given such as theplaying device 102 takes the lead to perform control, but should not belimited to this, and the output device 103 can have the lead forcontrol.

According to a second embodiment, description will be made of a casethat the output device 103 has the lead for control. In this case, asopposed to the case in the first embodiment, the output device 103performs a request as to the playing device 102, and the playing device102 responds to the request from the output device 103. That is to say,basically, each configuration and processing content of the playingdevice 102 and output device 103 of the first embodiment are mutuallyswitched.

FIG. 12 is a block diagram showing a configuration example of theplaying device 102 in this case. As shown in FIG. 12, in this case, theplaying device 102 has an information providing unit 212 instead of therestoration gamut conversion control unit 162. The information providingunit 212 is similar to the information providing unit 182 of the outputdevice 103 in FIG. 5 and has information relating to the playing device102, and supplies information relating to the playing device 102 to thepartner device (in this case, the output device) via the communicationunit 165, based on the request from the output device 103.

FIG. 13 is a block diagram showing a configuration example of the outputdevice 103 in this case. As shown in FIG. 13, in this case the outputdevice 103 has a restoration gamut conversion control unit 222 insteadof the information providing unit 182 in FIG. 5. The restoration gamutconversion control unit 222 performs control processing of therestoration processing and gamut conversion processing, similar to therestoration gamut conversion control unit 162 in FIG. 4. However, therestoration gamut conversion control unit 222 performs controlprocessing of the restoration processing and gamut conversion processingfrom the output device 103 side. The restoration gamut conversioncontrol unit 222 has a restoration conversion state confirming unit 231,information exchange unit 232, and determining unit 233. Thesecorrespond respectively to the restoration conversion state confirmingunit 171, information exchange unit 172, and determining unit 173 inFIG. 4. Other than whether or not the device itself if the playingdevice 102 or the output device 103 is basically the same.

[Flow of Processing of Output Device]

In this case, the output device 103 executes output control processingthat is basically similar to the playing control processing executed bythe playing device 102 in the first embodiment (FIG. 8).

An example of flow of the output control processing executed by theoutput device 103 will be described with reference to the flowchart inFIG. 14.

Upon output control processing starting, in step S301 the informationexchange unit 232 confirms communication with the playing device 102,and in step S302 determines whether or not bi-directional communicationwith the playing device 102 is possible. In the case determination ismade that bi-directional communication is possible, the flow is advancedto step S303.

In step S303, the information exchange unit 232 performs an inquiry tothe playing device 102 about restoration processing functionality,confirms the restoration processing capability of the playing device102, and in step S304 determines whether or not restoration processingcan be executed with the playing device 102. In the case that theplaying device 102 has a restoration processing unit 163 anddetermination is made that restoration processing can be executed withthe playing device 102, the flow is advanced to step S305.

In step S305 the determining unit 233 determines whether or notrestoration processing can be executed with the output device 103, i.e.whether or not the output device 103 has a restoration processing unit183 and a gamut conversion processing unit 184. In the casedetermination is made that the output device 103 cannot executerestoration processing, the flow is advanced to step S306.

In step S306, the information exchange unit 232 accesses the playingdevice 102, and supplies gamut information of the output device to theplaying device 102. In step S307, the information exchange unit 232accesses the playing device 102, and causes the playing device 102 toexecute a comparison (gamut comparison) of the gamut of the image dataread out from the optical disc 110 (image data gamut) and the gamut ofthe output device 103 (output gamut).

In step S308 the determining unit 233 obtains the comparison resultsthereof, and determines whether or not the output gamut is “completely”small as to the image data gamut. In the case that a portion outside ofthe image data gamut is included in the output gamut, and the outputgamut is not “completely” small as to the image data gamut, the flow isadvanced to step S309.

In step S309, the information exchange unit 232 access the playingdevice 102, causes the playing device 102 to perform restorationprocessing using the restoration metadata attached to the image data,and restores the gamut before gamut conversion of the image data.

That is to say, in this case, restoration processing cannot be performedwith the output device 103 (the output device 103 does not haverestoration processing functionality), and restoration processing isneeded (portions outside of the image data gamut are included in theoutput gamut), so the output device 103 causes the playing device 102 toexecute restoration processing.

Upon the restoration processing ending, in step S310 the informationexchange unit 232 access the playing device 102, and performsconfirmation of the device conditions for gamut conversion processing tothe playing device 102. Based on the confirmation results thereof, thedetermining unit 233 determines in step S311 whether or not the playingdevice 102 satisfies the device conditions.

The device conditions for the gamut conversion processing is similar tothe case of the first embodiment, so the description thereof will beomitted.

In the case determination is made that the device conditions for thegamut conversion processing do not hold, the flow is advanced to stepS312. That is to say, for example, in the case that the manufacturingsource of the playing device 102 and output device 103 mutually differ,or the version of gamut conversion algorithm is higher for the playingdevice 102, the flow is advanced to step S312.

In step S312, the information exchange unit 232 access the playingdevice 102, and causes the playing device 102 to execute maincompression. In step S313 the communication unit 165 obtains the maincompression data generated in step S312 from the playing device 102.Upon obtaining the main compression data, the flow is advanced to stepS322.

Also, in the case determination is made in step S311 that the deviceconditions for the gamut conversion processing holds, the flow isadvanced to step S314. That is to say, for example, in the case that themanufacturing source for the playing device 102 and output device 103are the same, or the version of the gamut conversion algorithm is higherfor the output device 103, the flow is advanced to step S314.

In step S314 the communication unit 181 obtains the image data subjectedto restoration processing (restored data) and the gamut metadata thereoffrom the playing device 102. Upon obtaining the restored data, the flowis advanced to step S321.

That is to say, in this case, it is more desirable for the gamutconversion processing to be executed with the output device 103, so theoutput device 103 obtains the image data of which the gamut has beenrestored from the playing device 102.

Also, in the case determination is made in step S308 that the gamut ofthe output device 103 is completely small, the flow is advanced to stepS312. That is to say, in this case, restoration processing isunnecessary, so the processing in step S309 and so forth is skipped, andthe flow is advanced to step S312. That is to say, main compression isperformed with the playing device 102.

In the case determination is made in step S305 that the output device103 can execute the restoration processing, the flow is advanced to stepS315. In step S315 the information exchange unit 232 exchangesinformation with the playing device 102, and confirms the deviceconditions for the restoration processing as to the playing device 102.Based on the confirmation results thereof, the determining unit 233determines in step S316 whether or not the playing device 102 satisfiesthe device conditions.

The device conditions for the restoration processing are similar to thecase of the first embodiment, so the description thereof will beomitted.

In the case determination is made in step S316 that device conditionsfor the restoration processing as described above do not hold, the flowis returned to step S306. That is to say, for example, in the case thatthe manufacturing source of the playing device 102 and output device 103mutually differ, or the version of restoration algorithm is higher forthe playing device 102, the flow is returned to step S306. In this case,control is performed such that, when restoration processing isnecessary, this is executed by the playing device 102.

Also, in the case determination is made in step S316 that deviceconditions for the restoration processing hold, the flow is advanced tostep S317. That is to say, for example, in the case that themanufacturing source for the playing device 102 and output device 103are the same, or the version of the restoration algorithm is higher forthe output device 103, the flow is advanced to step S317.

In step s317 the communication unit 181 obtains the temporarycompression data, together with the gamut metadata and restorationmetadata, from the playing device 102. Upon the temporary compressiondata being obtained, the flow is advanced to step S318.

In step S318, the determining unit 233 performs a gamut comparison ofthe image data gamut and output gamut. In step s319 the determining unit233 determines whether or not the gamut of the output device 103 (outputgamut) is completely small as to the image data gamut.

In the case determination is made that the output gamut includes aregion outside of the image data gamut, and is not completely small, theflow is advanced to step S320. In step S320 the restoration processingunit 183 executes restoration processing using restoration metadata, andrestores the gamut of the temporary compression data to before gamutconversion. Upon the gamut being restored, the flow is advanced to stepS321.

Also, in step S319, in the case determination is made that the outputgamut is included in the image data gamut for all of the hues and iscompletely small, the flow is advanced to step S321 without performingrestoration processing.

That is to say, in this case, control is performed such that, whenrestoration processing is necessary, this is executed by the outputdevice 103.

In step S321 the gamut conversion processing unit 184 subject the gamutof the image data (temporary compression data or image data of which thegamut has been restored) is subjected to main compression to the outputgamut. Upon main compression ending, the flow is advanced to step S322.

In step S322, the output unit 185 outputs the main compression data, andends the output control processing.

Also, in step S304, in the case determination is made that restorationprocessing by the playing device 102 is impossible, the flow is advancedto step S323. The determining unit 233 determines in step S323 whetheror not the output device 103 can execute the restoration processing.

In the case determination is made that restoration processing can beexecuted with the output device 103, the flow is returned to step S317.That is to say, in this case, execution of restoration processing withthe playing device 102 is impossible, and execution of restorationprocessing is possible with the output device 103, so control isperformed such that the restoration processing is performed with theoutput device 103.

Also, in the case determination is made in step S323 that execution ofrestoration processing by the output device 103 is impossible, the flowis advanced to step S324.

In step S324, the various units of the output device 103 executes thegamut conversion control processing that controls the processingrelating to gamut conversion. That is to say, in this case, restorationprocessing cannot be performed with either the playing device 102 or theoutput device 103. Thus, the various units of the output device 103execute the gamut conversion control processing so that at least gamutconversion processing can be performed. Details of this gamut conversionprocessing will be described later.

Upon gamut conversion processing ending, the output control processingis ended.

Also, in the case determination is made in step S302 that bi-directionalcommunication cannot be performed with the playing device 102, the flowis advanced to step S325. In step S325, the restoration gamut conversioncontrol unit 222 causes the various units to execute error processing,and ends the output control processing. That is to say, in this case,bi-directional communication cannot be performed between the playingdevice and output device (information necessary for restorationprocessing and gamut conversion cannot be exchanged), and the output ofthe image data is stopped.

Next, an example of flow of gamut conversion control processing that isexecuted in step S324 in FIG. 14 will be described with reference to theflowchart in FIG. 15.

Upon the gamut conversion control processing starting, in step S341 theinformation exchange unit 232 inquires with the playing device 102 viathe communication unit 181, and confirms the gamut conversion capabilityof the playing device 102. In step S342 the determining unit 233determines whether or not gamut conversion is possible with the playingdevice 102, i.e. whether or not the playing device 102 has a gamutconversion processing unit 164, based on the confirmation resultsthereof. In the case determination is made that gamut conversion ispossible, the flow is advanced to step S343.

In step S343, the determining unit 233 determines whether or not gamutconversion is possible with the output device 103. In the casedetermination is made that gamut conversion is impossible, the flow isadvanced to step S344.

In step S344 the information exchange unit 232 transmits gamutinformation of the output device 103 to the playing device 102, via thecommunication unit 181. In step S345 the information exchange unit 232accesses the playing device 102 and causes the playing device 102 toexecute main compression. In step S346 the communication unit 181obtains the main compression data obtained with the playing device 102.Upon obtaining the main compression data, the flow is advanced to stepS351.

Also, in the even determination is made in step S343 that gamutconversion can be executed with the output device 103, the flow isadvanced to step S347. In step S347 the information exchange unit 232exchanges information with the playing device 102, and confirms thedevice conditions for gamut conversion processing. The device conditionsare similar to the device conditions described above, so the descriptionthereof will be omitted. In step S348 the determining unit 233determines whether or not the device conditions hold.

In the case determination is made that the device conditions for thegamut conversion processing do not hold, the flow is returned to stepS344. That is to say, for example, in the case that the manufacturingsource for the playing device 102 and output device 103 mutually differ,or the version of the gamut conversion algorithm is higher for theplaying device 102, the flow is returned to step S344.

In this case, gamut conversion can be performed by both the playingdevice 102 and output device 103, but it is more desirable for theplaying device 102 to perform the gamut conversion, so controls areperformed such that gamut conversion is performed by the playing device102.

Also, in the case determination is made in step S348 that the deviceconditions for the gamut conversion processing hold, the flow isadvanced to step S349. That is to say, for example, in the case that themanufacturing source for the playing device 102 and output device 103are mutually the same, or the version of the gamut conversion algorithmis higher for the output device 103, the flow is advanced to step S349.

In this case, gamut conversion can be performed by both the playingdevice 102 and output device 103, but it is more desirable for theoutput device 103 to perform the gamut conversion, so controls areperformed such that gamut conversion is performed by the output device103.

In step S349, the communication unit 181 obtains temporary compressiondata, together with the gamut metadata, from the playing device 102. Instep S350, the gamut conversion processing unit 184 uses the gamutmetadata to subject the gamut of the obtained temporary compression datato the output gamut. Upon main compression ending, the flow is advancedto step S351.

In step S351 the output unit 185 outputs the main compression data, endsthe gamut conversion control processing, returns to step S324 in FIG.14, and ends the output control processing.

Also, in the case determination is made in step S342 that execution ofgamut conversion by the playing device 102 is impossible, the flow isadvanced to step S352. In step S352 the determining unit 233 determineswhether or not gamut conversion can be executed with the output device103. In the case determination is made that gamut conversion with theoutput device 103 is possible, the flow is returned to step S349. Inthis case, controls are performed so that main compression is performedwith the output device 103.

In the case determination is made in step S352 that the output device103 also cannot perform gamut conversion, the flow is advanced to stepS353. In step S353 the restoration gamut conversion control unit 222causes the various units to execute error processing, ends the gamutconversion control processing, returns to step S324 in FIG. 14, and endsthe output control processing. That is to say, in this case, sinceneither the playing device 102 nor output device 103 can perform gamutconversion, output of the image data is stopped.

By executing processing such as described above, the output device 103controls the restoration processing and gamut conversion processing.

[Flow of Processing of Playing Device]

Next, processing to be executed with the playing device 102 will bedescribed. The playing device 102 executes playing control processing asto the control processing of the output device 103 described above, andresponds to requests from the output device 103. An example of flow ofthe playing control processing will be described with reference to theflowchart in FIG. 16.

Upon the playing control processing starting, in step S371 thecommunication unit 165 confirms communication with the output device103, and in step S372 determines whether or not bi-directionalcommunication is possible. In the case determination is made thatbi-directional communication is possible, the flow is advanced to stepS373.

In step S373 the various units of the playing device 102 executerestoration conversion control processing to link with the output device103 and execute restoration conversion control processing to properlycontrol the execution of the restoration processing and gamut conversionprocessing. Details of the restoration conversion control processingwill be described later.

In step S374 the information providing unit 212 determines whether toend the playing control processing. Until the playing control processingis ended in this step S374, the restoration conversion controlprocessing in step S373 is repeatedly executed.

In the case determination is made in step S374 to end the playingcontrol processing, the output control processing is ended. Also, in thecase that bi-directional communication is impossible, output of theimage data is stopped, so in the case determination is made in step S372that bi-directional communication is impossible, the restorationconversion control processing is omitted and the output controlprocessing is ended.

Next, a detailed example of flow of the restoration conversion controlprocessing executed in step S373 in FIG. 16 will be described withreference to the flowchart in FIG. 17.

Upon restoration conversion control processing starting, the informationproviding unit 212 determines in step S391 whether restorationprocessing capability has been confirmed from the output device 103. Inthe case determination is made that restoration processing capability isconfirmed via the communication unit 165, the flow is advanced to stepS392. In step S392, the information providing unit 212 notifies therestoration processing capability of the playing device 102 to theoutput device 103, via the communication unit 165.

Upon notification ending, the flow is advanced to step S393. Also, inthe case determination is made in step S391 that restoration processingcapability has not been confirmed, the processing in step S392 isskipped, and the flow is advanced to step S393.

In step S393 the information providing unit 212 determines whether ornot gamut conversion capability has been confirmed from the outputdevice 103. In the case determination is made that gamut conversioncapability has been confirmed via the communication unit 165, the flowis advanced to step S394. In step S394, the information providing unit212 notifies the gamut conversion capability of the playing device 102to the output device 103, via the communication unit 165.

Upon notification ending, the flow is advanced to step S395. Also, inthe case determination is made in step S393 that gamut conversioncapability has not been confirmed, the processing in step S394 isskipped, and the flow is advanced to step S395.

In step S395 the information providing unit 212 determines whether ornot the device conditions for the restoration processing have beenconfirmed form the output device 103. An example of a device conditionfor restoration processing is as described above.

In the case determination is made that device conditions for therestoration processing have been confirmed via the communication unit165, the flow is advanced to step S396. In step S396 the informationproviding unit 212 notifies the confirmation results of the deviceconditions for restoration processing of the playing device 102 to theoutput device 103, via the communication unit 165.

Upon ending the notification, the flow is advanced to step S397. Also,in the case determination is made in step S395 that the deviceconditions for the restoration processing have not been confirmed, theprocessing in step S396 is skipped, and the flow is advanced to stepS397.

In step S397 the information providing unit 212 determines whether ornot the device conditions for the gamut conversion processing have beenconfirmed from the output device 103. An example of a device conditionfor gamut conversion processing is as described above.

In the case determination is made that device conditions for the gamutconversion processing have been confirmed via the communication unit165, the flow is advanced to step S398. In step S398 the informationproviding unit 212 notifies the output device 103 of the confirmationresults of the device conditions for gamut conversion processing of theplaying device 102.

Upon the notification ending, the flow is advanced to step S399. Also,in the case determination is made in step S397 that device conditionsfor the gamut conversion processing have not been confirmed, theprocessing in step S398 is skipped, and the flow is advanced to stepS399.

In step S399, the information providing unit 212 determines whether ornot a gamut comparison has been requested by the output device 103 viathe communication unit 165. In the case determination is made that agamut comparison has been requested, the flow is advanced to step S400.In step S400 the information providing unit 212 obtains the gamutinformation of the output device via the communication unit 165, usesthe gamut information thereof to perform a comparison of the image datagamut and output gamut, and notifies the comparison results thereof tothe output device 103 via the communication unit 165.

Upon the notification ending, the flow is advanced to step S401. Also,in the case determination is made in step S399 that a gamut comparisonhas not been requested from the output device 103, the processing instep S400 is skipped, and the flow is advanced to step S401.

In step S401 the information providing unit 212 determines whether ornot restoration processing has been requested from the output device 103via the communication unit 165. In the case determination is made thatrestoration processing has been requested, the flow is advanced to stepS402. In step S402 the information providing unit 212 causes therestoration processing unit 163 to perform restoration processing of thetemporary compression data, and supplies the restored data obtained bythe restoration processing thereof to the output device 103.

Upon the restoration data having been supplied, the flow is advanced tostep S403. Also, in the case determination is made in step S401 thatrestoration processing has not been requested, the processing in stepS402 is skipped, and the flow is advanced to step S403.

In step S403, the information providing unit 212 determines whether ornot main compression has been requested from the output device 103 viathe compression unit 165. In the case determination is made that maincompression has been requested, the flow is advanced to step S404. Instep S404 the information providing unit 212 obtains the gamutinformation of the output device from the output device 103 via thecommunication unit 165, causes the gamut conversion processing unit 164to perform main compression, and supplies the main compression dataobtained with the main compression thereof to the output device 103.

Note that at this time, in the case that restoration processing isnecessary, the information providing unit 212 causes the restorationprocessing unit 163 to perform restoration processing, and subsequentlycauses the gamut conversion processing unit 164 to perform maincompression, as appropriate.

Upon main compression data having been supplied, the restorationconversion control processing is ended, the flow is returned to stepS373 in FIG. 16, and the processing in step S374 and thereafter isperformed.

Also, in the case determination is made in step S403 that maincompression has not be requested, the processing in step S404 isskipped, the restoration conversion control processing is ended, theflow is returned to step S373 in FIG. 16, and the processing in stepS374 and thereafter is performed.

As described above, by performing control of the restoration processingand gamut conversion processing according to various conditions, even ina case of handling content with multiple devices, the playing device 102and output device 103 can suppress unnecessary execution of restorationprocessing and gamut conversion processing, and execution of restorationprocessing and gamut conversion processing by inefficient methods, andcan perform restoration and gamut conversion of content more reliablyand properly.

3. Third Embodiment Gamut Conversion Control

Next, processing of the playing device 102 and output device 103 in thecase that the playing data is temporary compression data and only gamutmetadata is attached (i.e., in the case that the processing in step S108is performed in the recording control processing in FIG. 6) will bedescribed.

In this case, control relating to restoration processing is notperformed, and the processing controls only the gamut compression. Thatis to say, as in the first embodiment, in the case that the playingdevice 102 has the lead, the playing device 102 executes the gamutconversion control processing described with reference to the flowchartin FIG. 9. The output control processing of the output device 103corresponding thereto is basically similar to the case in the firstembodiment. However, control relating to the restoration processing isomitted.

Also, as in the second embodiment, in the case that the output device103 has the lead, the output device 103 executes the gamut conversioncontrol processing described with reference to the flowchart in FIG. 15.The playing control processing of the playing device 102 correspondingthereto is basically similar to the second embodiment. Note however,control relating to the restoration processing is omitted.

As described above, by performing control of the restoration processingand gamut conversion processing according to various conditions, even ina case of handling content with multiple devices, the playing device 102and output device 103 can suppress unnecessary execution of restorationprocessing and gamut conversion processing, and execution of restorationprocessing and gamut conversion processing by inefficient methods, andcan perform restoration and gamut conversion of content more reliablyand properly.

4. Fourth Embodiment Main Compression Data Control

Next, processing of the playing device 102 and output device 103 in thecase that the playing data is main compression data (i.e., in the casethat the processing in step S103 is performed in the recording controlprocessing in FIG. 6) will be described.

An example of flow of the playing control processing in the case thatthe playing data is main compression data will be described withreference to the flowchart in FIG. 18.

In this case, upon the playing control processing starting, in step S421the determining unit 173 of the playing device 102 (FIG. 4) supplies themain compression data read out from the optical disc 110 to thecommunication unit 165. Upon the main compression data having beentransmitted, the playing control processing is ended.

Next, an example of flow of the playing control processing in the casethat the output data is main compression data will be described withreference to the flowchart in FIG. 19.

In this case, upon the output control processing having started, in stepS441 the communication unit 181 of the output device 103 (FIG. 5)obtains the main compression data supplied from the playing device 102.The communication unit 181 supplies the obtained main compression datato the output unit 185. In step S442 the output unit 185 outputs themain compression data thereof.

Upon the main compression data having been output, the output controlprocessing is ended.

As described above, by performing playing control processing and outputcontrol processing, the playing device 102 and output device 103 canproperly output without performing unnecessary gamut conversionprocessing and restoration processing and the like as to the image datasubjected to main compression.

5. Fifth Embodiment Specific Configuration Example of InformationProcessing System

Next, a specific example of the information processing system describedabove and various processes will be described. First, a specific exampleof a information processing system 100 will be described. FIG. 20 is adiagram showing a specific configuration example of the informationprocessing system. An information processing system 400 shown in FIG. 20has a monitor 402 connected to a digital still camera 401 digital stillcamera 401 via an HDMI (High-Definition Multimedia Interface) cable 403.

The digital still camera 401 images a subject and generates image data(content). The digital still camera 401 records the image data thereofon a recording medium such as a built-in hard disk or flash memory orthe like. The digital still camera 401 further reads out and plays theimage data recorded on the recording medium thereof, supplies this tothe monitor 402 via the HDMI cable 403, and displays the image thereof.

In the case of this example, the digital still camera 401 corresponds tothe recording device 101 and playing device 102, and the monitor 402corresponds to the output device 103. The HDMI cable 403 is acommunication bus that connects the playing device and output device,and corresponds to the optical disc 110.

That is to say, for example, the digital still camera 401 has aconfiguration such as shown in FIG. 3 and FIG. 4, and the monitor 402has a configuration such as shown in FIG. 5.

The information processing system 400 performs image data gamutconversion and restoration as appropriate, as with the informationprocessing system 100. That is to say, the digital still camera 401 andmonitor 402 mutually exchange information, appropriately determine whichdevice will perform the restoration processing and gamut conversionprocessing, and control the execution of the processing thereof.

[Gamut Conversion Overview]

Next, an overview of gamut conversion will be described. FIG. 21 is adiagram showing an example of a format of chromaticity information.

Still images that are imaged with the digital still camera 401 arerecorded in a saturation/color difference signal space called a sYCCcolor-space. sYCC is established by IEC (International ElectrotechnicalCommission) (International Electrotechnical Commission), and is acolor-space for still image recording which is an internationalstandards definition of IEC 61966-2-1 AMD (support documentation ofsRGB). 95% or more of the colors that humans can perceive can berecorded thereby, and it has a gamut sufficient to record colors thatdigital still cameras for consumer use can sense. In this embodiment,recorded moving picture content becomes a still image, and recordeddevice gamut information becomes sYCC.

A first gamut conversion is performed at the time of hard diskrecording. The temporary output device gamut of this compression is ansRGB space, and the chromaticity information thereof is as in the graphshown in FIG. 21A and in the table shown in FIG. 21B. sRGB (StandardRGB) is a color-space specified by IEC as colors for a standard displayobserved in a certain standard viewing environment. This is a stillimage recording color-space having an international standards definitionof IEC 61966-2-1.

As shown in FIG. 22A, when the gamut of a certain device is expressedwith the YCC (Y, Cb, Cr) space (gamut 411), a cross-sectional plane thatis cross-cut with a same hue plane, as shown in FIG. 22B, can beexpressed with a YC2 dimensional plane having luminance Y as thevertical axis and saturation C as the horizontal axis (gamut 412). Thegamut form on this plane can be approximated with a triangle that linksa white point, black point, and Cusp point, as in the gamut 412 shown inFIG. 22, if the YC coordinates of the maximum saturation points (Cusp)can be obtained. Using this nature, by holding the YC coordinates of theCusp points (Cusp information) on several representative hue faces (H)in a numerical value table, the gamut 411 of the device can beapproximately defined. A table of the YC coordinates (Cusp information)of the maximum saturation points (Cusp) of the representative hues iscalled a Cusp table.

FIG. 23 is a diagram showing an example of the Cusp table thereof. TheCusp table in FIG. 23 has converted the format of the chromaticityinformation shown in FIG. 21, and shows an sRGB color-space, similar tothe chromaticity information in FIG. 21.

The graph 421-1 has graphed the luminance (Y) of the Cusp points foreach hue (H). The graph 421-2 has graphed the saturation (C) of the Cusppoints for each hue (H). Also, the table 422 has formed the values ofthe luminance (Y) and saturation (C) of representative hues (H) into atable. Performing interpolation processing using the values in the table422 and obtaining the luminance and saturation between therepresentative hues (intermediate hues) can also be readily performed,whereby the graph 421-1 and graph 421-2 and table 422 have approximatelyequivalent information. Thus, the Cusp table only has to show the YCcoordinates of the Cusp points for at least each representative hue, andthe format thereof is optional.

[Gamut Conversion]

The gamut conversion processing unit 164 of the digital still camera 401and the gamut conversion processing unit 184 of the monitor 402 performgamut conversion (main compression or temporary compression) using aCusp table such as described above. Details of the gamut conversionprocessing will be described below. A case wherein the gamut conversionprocessing unit 164 performs gamut conversion using the gamut (sRGB)shown in the Cusp table in FIG. 23 as the gamut after conversion (targetgamut) will be described below as an example. Even in the case that thetarget gamut is another gamut, or in the case that the gamut conversionprocessing unit 194 performs gamut conversion, the gamut conversionprocessing basically is executed similarly.

An example of the flow of gamut conversion processing will be describedwith reference to the flowchart in FIG. 24.

Upon the gamut conversion processing starting, the gamut conversionprocessing unit 164 performs calculation such as those shown below inExpression (1) through Expression (3), for example, so that . . . doesnot occur due to the gamut conversion, and converts the format of theinput content data from YCC (Yi, Cbi, Cri) to YCH (Yi, Ci, Hi), forexample (converts the coordinates system from YCC coordinates to YCHcoordinates).

$\begin{matrix}\left\lbrack {{Mathematical}\mspace{14mu} {Expression}\mspace{14mu} 1} \right\rbrack & \; \\{{Yi} = {Yi}} & (1) \\{{Ci} = \sqrt{{Cbi}^{2} + {Cri}^{2}}} & (2) \\\left\{ \begin{matrix}{{{if}\mspace{14mu} {Cri}} > 0} \\{{Hi} = {{\arctan \left( \frac{Cri}{Cbi} \right)} \cdot \frac{180}{\pi}}} \\{else} \\{{Hi} = {{{\arctan \left( \frac{Cri}{Cbi} \right)} \cdot \frac{180}{\pi}} + 360}}\end{matrix} \right. & (3)\end{matrix}$

Upon the format having been converted, in step S502 the gamut conversionprocessing unit 164 computes the YC coordinates information (Ycp, Ccp)of the maximum saturation point (Cusp point) for each hue Hi, of thetargeted gamut. Note that the target gamut is defined at the point intime that the gamut conversion processing is started (i.e., the gamutinformation is also held), whereby the YC coordinates information of theCusp point can be obtained from the target gamut information (e.g. YCCdata).

In step S503, the gamut conversion processing unit 164 specifies anon-mapping border and mapping limit border.

FIG. 25 is a diagram showing an example of a state of gamut conversion.In FIG. 25, the region surrounded by a thick line (region surrounded bya triangle having the white point, black point, and Cusp point as thevertex) is the final conversion destination region (Target compressedarea), i.e., the target gamut. A T-boundary (Target boundary) 431 is theedge (border) other than the Y-axis of the target region. Using thisT-boundary 431 as a standard, the border line that is smaller in thesaturation direction a small amount is a non-mapping border (U-boundary(Uncompressed boundary)) 432. The region surrounded by the Y-axis andthe U-boundary 432 is a non-mapping region, and the pixels includedherein are not subjected to gamut conversion (coordinate movement).Next, which amount of the region should be converted to the conversiondestination region needs to be specified. The border line for specifyinghow much the color of the moving picture content is spread out over thegamut is a mapping limit border (L-boundary (Limited boundary)) 433. Ingamut conversion, the L-boundary 433 is border line expanded farther inthe saturation direction than the T-boundary 431. That is to say, gamutconversion means to compress the region surrounded by the U-boundary 432and L-boundary 433 into a region (gray portion) surrounded by theU-boundary 432 and T-boundary 431.

To express only regarding the saturation direction, with gamutconversion, the coordinates a0in in FIG. 25 is moved to a0out, forexample. Note that the colors having higher saturation that theL-boundary 433 are all clipped by the T-boundary 431 (coordinates movedto above the T-boundary 431). For example, the coordinate of a1in inFIG. 25 is moved to about.

FIG. 26 is a diagram showing an example of an LU table. The LU table 441shown in FIG. 26 is a ratio (saturation ratio) of the saturation of thespecified non-mapping border (U-boundary 432) and mapping limit border(L-boundary 433), using the T-boundary 431 as a standard, and is tableinformation shown for each hue. In FIG. 26, the saturation ratio of theL-boundary and U-boundary for all of the hues is fixed (L-boundary is1.5, U-boundary is 0.75), but these values may be changed for each hue(H).

The determining method for the saturation ratio of the L-boundary andU-boundary is optional. For example, the gamut conversion processingunit 164 can hold an LU table 441 such as shown in FIG. 26 beforehand,or can obtain one externally.

Returning to FIG. 24, in step S504, the gamut conversion processing unit164 defines the conversion coefficient.

If we express the state of compression with a function when thesaturation ratio of the U-boundary 432 is “0.75” and the saturationratio of the L-boundary 433 is “1.5”, this can be shown with a curve 451as shown in FIG. 27, for example. This curve 451 is called a mappingfunction. A range having a slope of “1” shows a non-mapping region. Thegamut conversion indicates that the range surrounded by the U-boundary432 and L-boundary 433 on the horizontal axis is compressed into aregion surrounded by the U-boundary 432 and T-boundary 431 on thevertical axis. Converting methods at this time are optional, and variousmethods may be considered. For example, solid line 451A indicates linearcompression. Broken line 451B is an example of smoothly bending afunction and gradually compressing. Dashed-dotted line 451C is notcompression, and indicates gamut clip to the T-boundary 431.

That is to say, depending on the form of the curve 451 of this range,for example in FIG. 25, the ratio of the distance to the T-boundary 431of a0out which is the movement destination of a0in and the distance tothe U-boundary 432 (r:s) is determined, wherein the ratio of thedistance to the L-boundary 433 and the distance to the U-boundary 432 isp:q. In other words, the function shown with the curve 451 (conversionfunction) shows the compression rate (R_ccomp) in the saturationdirection of a pixel targeted for a certain processing, and from theoutput values of this function, a virtual clip border for the pixeltargeted for processing is determined.

The mapping function is determined by depending on the values of theL-boundary 433 and U-boundary 432, so if the values of the L-boundary433 and U-boundary 432 change for each hue, the mapping functions alsowill change.

Returning to FIG. 24, in step S505 the gamut conversion processing unit164 determines the virtual clip border.

The gamut conversion processing unit t164 uses the saturation Ci of thepixel targeted for processing, and references the conversion functiondefined in the processing in step S504. However, the conversion functionis a value wherein the saturation in the T-boundary 431 is normalized to“1” so the saturation Ci_c in the T-boundary 431 having the sameluminance as the pixel targeted for processing needs to be found. If wesay that the YC coordinates of the pixel targeted for processing(processing target pixel) is (Yi, Ci), then the saturation Ci_c, in theT-boundary 431 having the same luminance as the pixel targeted forprocessing as shown in FIG. 28, for example, can be found as thesaturation of the intersection of the line linking the white point andCusp point and the line linking the processing target pixel (Yi, Ci) andluminance point (Yi, 0) of the processing target pixel on the Y-axis.

Using the intersection of the saturation c and the saturation Ci of theprocessing target pixel, the saturation Ci_norm for referencing theconversion function can be computed as shown in Expression (4) below.

$\begin{matrix}\left\lbrack {{Mathematical}\mspace{14mu} {Expression}\mspace{14mu} 2} \right\rbrack & \; \\{{Ci\_ norm} = \frac{Ci}{Ci\_ c}} & (4)\end{matrix}$

For example, the gamut conversion processing unit 164 determines thesaturation direction compression rate R_ccomp of the processing targetpixel, referencing the conversion function shown with the curve 451 inFIG. 27 using the saturation Ci_norm. Upon the R_ccomp having beendetermined, a virtual clip border of the processing target pixel(V-boundary (Virtual clip boundary)) can be determined. Thus, bydetermining the virtual clip border (V-boundary), the gamut conversioncan be considered as processing that repeatedly performs the gamut clipas to the virtual clip border.

FIG. 29 is a diagram to compare the state of gamut clip and gamutconversion. FIG. 29A is a schematic diagram showing the state of gamutclip. Gamut clip indicates moving a color that is outside the targetgamut onto the T-boundary 431 which is the target gamut border (clips tothe T-boundary 431), as shown in FIG. 29A. For example, in FIG. 29A, thecoordinates of the processing target pixel shown with a white circle ismoved to the clip point on the T-boundary 431, which is shown with ablack circle.

FIG. 29B is a schematic diagram showing the state of gamut conversion.As described above, gamut conversion is to move the processing targetpixel onto a virtual clip border (V-boundary) corresponding to theprocessing target pixel. For example, in FIG. 29B, the coordinates ofthe processing target pixel 461 is moved to the clip point 464 on theV-boundary 471B. That is to say, gamut conversion can be considered asequivalent to performing similar processing as in the case of the gamutclip in FIG. 29A for each processing target pixel.

For example, to describe the Cusp point, the YC coordinates (Ycp, Ccp_V)of the clip point Cusp_V of the Cusp point having YC coordinates (Ycp,Ccp) can be computed as in the Expression (5) below, using thesaturation direction compression rate R_ccomp.

[Mathematical Expression 3]

Cusp_V=(Ccp_V,Ycp)=(R_ccomp×Ccp,Ycp)  (5)

The virtual clip border (V-boundary) 471 is determined from the YCcoordinates of the clip point Cusp_V. For example, the virtual clipborder (V-boundary) 471 of the Cusp Point is made up of a line segmenthaving the clip point Cusp_V and the white point as both ends, and aline segment having the clip point Cusp_V and the black point as bothends, as shown in FIG. 30.

That is to say, this V-boundary 471 is determined by the above-describedconversion function and the ratio of the distance to the L-boundary 433of the processing target pixel and distance to the U-boundary 432 (p:q).In other words, processing target pixels having the same ratio (p:q) ofthe distance to the L-boundary 433 and distance to the U-boundary 432share the V-boundary 471.

Returning to FIG. 24, in step S506, the gamut conversion processing unit164 performs mapping processing.

FIG. 31 is a diagram showing an example of the state of the gamutconversion mapping. With the mapping, as shown in FIG. 31 for example,an isobestic point in the clip direction is set on the Y-axis, andmapping is performed in the direction facing the isobestic point thereofon the virtual clip border (V-boundary) 471.

In the case of the example in FIG. 31, a point having the same luminanceas the luminance Ycp of the Cusp on the Y-axis is set as the isobesticpoint, and mapping is performed in the direction (arrow) facing theisobestic point thereof.

It goes without saying that in which direction to clip on the virtualclip border (V-boundary) 471 is optional, and the position of theisobestic point is also optional. Also, multiple isobestic points may beset. In this case, for example, mapping is performed in a directionwherein the directions facing the various isobestic points aresynthesized at a predetermined ratio.

With such clipping, the final mapping point (Co, Yo) is determined.

Returning to FIG. 24, in step S507 the gamut conversion processing unit164 converts the form of the output content data. If the CY coordinatesof the final mapping point obtained with the processing in step S506 are(Co, Yo), the gamut conversion processing unit 164 performs conversionfrom the YCH coordinate system to the YCC coordinate system as shown inExpression (6) through Expression (8) below, and calculates the YCCcoordinates Pout (Yo, Cbo, Cro) of the final mapping point.

Ho=Hi  [Mathematical Expression 4]

Accordingly,

Yo=Yo  (6)

Cbo=Co·cos(Ho)  (7)

Cro=Co·sin(Ho)  (8)

Upon the YCC coordinates of the final mapping point having beencomputed, the gamut conversion processing is ended.

[Metadata]

Next, a configuration of the gamut metadata and restoration metadatawill be described in detail. The gamut metadata is made up of datashowing a gamut conversion target range. For example, a Cusp table(graph 421-1 and graph 421-2, or table 422) such as shown in FIG. 23 isadded to the image data subjected to gamut conversion as the gamutmetadata.

Also, restoration metadata generated by the restoration metadatagenerating unit 155 (FIG. 3) may include any sort of data as long asthis is data referenced in the event of restoration processing, but forexample, has the following three types of data.

The first data type is data indicating a gamut conversion target range.For example, this is a LU table 441 shown in FIG. 26. That is to say, byreferencing the LU table 441, how far the data before gamut conversionhad spread, or where the data region not subjected to gamut conversionis, can be confirmed. Note that the format of the LU table 441 isoptional. For example, the saturation ratio of the L-boundary andU-boundary for each representative hue (e.g., every 10 degrees) may beformed into a table. In this case, the saturation ratio of theL-boundary and U-boundary of the intermediate hues betweenrepresentative hues may be computed by performing interpolationprocessing using the saturation ratio of the L-boundary and U-boundaryof the representative hues.

The second type of data is data indicating the degree of gamutconversion (restoration). For example, this is an inverse function(restoration function) of the gamut conversion function shown in FIG.27. FIG. 32 is a diagram showing an example of the restoration function.FIG. 32A shows the restoration functions in a graph, and FIG. 32B showsthe restoration function in a table of representative points.

A curve 491 in the graph shown in FIG. 32A is the inverse function ofthe curve 451 in FIG. 27 (in the case of solid line 451A) in the 0through T-boundary range on the horizontal axis (normalized Cout) (0through L-boundary range on the vertical axis (normalized Cin)).

However, points in the portion greater than the T-boundary on thehorizontal axis is clipped to the T-boundary in the event of gamutconversion processing, so restoration is impossible. Accordingly, thecurve 491 which is a restoration function in FIG. 32A does not includeportions greater than the T-boundary.

A table 492 in FIG. 32B is a table of values (e.g., dispersion data ofinput (normalized Cout (R-ccomp)) in spacing increments of 0.0625) onthe vertical axis (normalized Cin) for the representative points on thecurve 491 in FIG. 32A. Intermediate points not on the table can beobtained by interpolation processing, so the table 492 can be seen asequivalent to the curve 491 shown in FIG. 32A.

Thus, the restoration function indicates the pixels in which portionsare compressed or expanded by what amount. The format of the datashowing the restoration function herein is optional, and other than theabove-descriptions, for example a mathematical expression or the likemay be used.

The third type of data is data indicating the direction of gamutconversion (restoration). For example, this may be the isobestic tableused in the event of gamut conversion. With the above descriptions, theisobestic point for each hue is described as the point on the Y-axis ofthe luminance Ycp of the Cusp for each hue. Accordingly, in this case,for example as in graph 493 shown in FIG. 33, the isobestic point tableis the same as the Cusp luminance Ycp table.

It goes without saying that the isobestic point can be set to anoptional position, so the isobestic point table is independently set,and will not necessarily be the same as the Cusp luminance Ycp table.

Also, the format of the isobestic point table is also optional as withthe restoration function and LU table and so forth, and may be expressedwith any format such as a graph, table of representative points,mathematical expression or the like.

[Recording Format]

The image data thus subjected to gamut conversion is saved on an opticaldisc 110 as a data length 16-bit image in a Tiff file format, forexample. In this case, the gamut metadata and restoration metadatahaving data such as described above is embedded in the image data as aTiff “Private Tag”, for example.

FIG. 34 is a diagram showing an example of a recording format of thegamut metadata. The gamut metadata prepares a tag (Tag) called“GamutMeta” in the Tiff “Private Tag”, for example, and can be stored inthe “GamutMeta Tag” thereof.

A Tiff “Directory Entry” of the “GamutMeta Tag” is in a configuration asshown on the left side in FIG. 34. The form of the variable making upthe tag (Tag) is set as “7”, indicating “Undefined”. As for the numberof variables, the Cusp information table is held for each of Y and C, so“2” is set. If the offset address to “Value” stored in an actual tableis “a”, then “Value” becomes a configuration as shown on the right sidein FIG. 34, for example. In the example in FIG. 34, the Cusp tables foreach of Y and C are defined by 37 tables in increments of hues of 10degrees.

FIG. 35 is a diagram showing an example of a recording format of therestoration metadata. The restoration metadata prepares a tag (Tag)called “ReprocMeta” in the Tiff “Private Tag”, for example, and can bestored in the “ReprocMeta Tag” thereof.

The Tiff Directory Entry of the “ReprocMeta Tag” is in a configurationsuch as shown on the left side of FIG. 20. In this case also, the formof the variable making up the tag (Tag) is set to “7”, indicating“Undefined”. However, as to the number of variables, “4” is set, sincethe types of restoration metadata are a total of four types: two typesof LU tables, a restoration function, and an isobestic point table. Ifthe offset address to “Value” stored in an actual table is “a”, then“Value” becomes a configuration as shown on the right side in FIG. 35,for example.

In the example in FIG. 35, the two types of tables of the L-boundary andU-boundary (L table data and U table data) and the isobestic point table(Cony table data) are defined by 37 double-form tables in increments of10 degrees. Also, the restoration function (Reproc func data) is definedas 17 double-form tables in increments of 0.0625.

In the case of a Tiff format, the image data and various metadata arerecorded on the optical disc 110 in a format such as described above. Itgoes without saying that the storage location of the image data andvarious metadata is optional, and may be a location other than theexample described above. Also, the image data format may be other thanTiff.

[Output Gamut]

Note that in the case of displaying the image on the monitor 402, thedigital still camera 401 obtains gamut information of the monitor 402via the HDI cable 403 beforehand. In this case, an exchange ofconnection information using an EDID (Extended Display IdentificationData) is performed in the negotiation at time of connections. At thistime, the gamut information of the monitor 402 is written into the EDID.Thus, the digital still camera 401 can obtain the gamut information ofthe monitor 402 at the time of connections with the monitor 402.

The gamut information (output gamut) of the monitor 402) may beinformation of any sort of format, but for example, may be a Cusp tableas shown in FIG. 36.

FIG. 36 is a diagram showing an example of the output gamut. Graph 521-1is a graph of the luminance (Y) of the Cusp points for each hue (H).Graph 521-2 is a graph of the saturation (C) of the Cusp points for eachhue (H). Also, table 522 is a table of the values of the luminance (Y)and saturation (C) of the representative hues (H). That is to say,similar to the case in FIG. 23, the Cusp table only has to show at leastthe YC coordinates of the Cusp points for each representative hue, andthe format thereof is optional.

[Control of Restoration and Compression]

Next, a specific example of restoration processing will be described. Anexample of the flow of restoration processing executed with therestoration processing unit 163 will be described with reference to theflowchart in FIG. 37.

Upon the restoration processing starting, in step S601 the restorationprocessing unit 163 converts the format of the playing content data,which is various types of data such as image data read out from theoptical disc 110 and so forth, from YCC (Yi, Cbi, Cri) to YCH (Yi, Ci,Hi). The conversion herein is performed as shown in Expression (1)through Expression (3), similar to the case of the time of recording,for example.

In step S602, the restoration processing unit 163 computes thecoordinates of the maximum saturation point (Cusp point) of the gamut ofeach hue Hi. The gamut information of the image data of the playingcontent data is provided in the Cusp table described with reference toFIG. 23. Accordingly, the restoration processing unit 163 calculates theCY coordinates of the Cusp point of the processing target hue Hi, with asimilar method as the case of gamut conversion at the time of recording.

In step S603 the restoration processing unit 163 obtains the non-mappingborder (U-boundary 432) and mapping limit border (L-boundary 433) suchas shown in FIG. 38 with a saturation ratio, for example. With temporarycompression, the gamut between the U-boundary 432 and L-boundary 433 isconverted to the gamut between the U-boundary 432 and T-boundary. Thatis to say, by obtaining the U-boundary 432 and L-boundary 433, therestoration processing unit 163 obtains the range subjected to gamutconversion. In other words, the restoration processing unit 163 obtainsthe restoration range which is a range wherein the gamut beforetemporary compression is restored.

Since an LU table (FIG. 26) is included in the restoration metadata, therestoration processing unit 163 can readily obtain the U-boundary 432and L-boundary 433 of the hue Hi by referencing the LU table.

In step S604 the restoration processing unit 163 references therestoration function (FIG. 32) include in the restoration metadata, andas shown in FIG. 39, determines the virtual restoration border(V-boundary) 471 corresponding to the saturation Ci of the processingtarget pixel (Ci, Yi).

In step S605 the restoration processing unit 163 subjects the processingtarget pixel to restoration mapping on the V-boundary 471 obtained bythe processing in step S604. The restoration processing unit 163references the isobestic point table (FIG. 33) included in therestoration metadata tables, and determines the isobestic point of theprocessing target hue Hi.

The restoration processing subjects the processing target pixel torestoration mapping from the isobestic point towards the directionfacing the processing target pixel, as shown in FIG. 40, for example.That is to say, the processing target pixel is moved (restorationmapping) to the intersection (final mapping point (Co, Yo)) between aline linking the isobestic point and the processing target pixel and theV-boundary 471.

In step S606 the restoration processing unit 163 converts and outputsthe format of the output content data which is image data subjected torestoration processing and so forth as described above, from YCH (Yi,Ci, Hi) to YCC (Yi, Cbi, Cri), and ends the restoration processing.

As described above, for example the gamut conversion processing unit 164performs a second gamut conversion (main compression) as describedabove, as to the image data for which the gamut is restored to beforethe temporary compression.

As described above, in the event that the digital still camera 401records image data on the optical disc 110, restoration metadata isgenerated, and added to the image data and recorded on the optical disc110, whereby the digital still camera and monitor 402 can readilyperform restoration processing as described above.

6. Sixth Embodiment Personal Computer

The above-described series of processing can be executed with hardware,or can be executed with software. In this case, for example, aconfiguration may be that of a personal computer such as shown in FIG.41.

In FIG. 41, a CPU (Central Processing Unit) 701 of a personal computer700 executes various types of processing according to a program storedin a ROM (Read Only Memory) 702 or a program loaded in a RAM (RandomAccess Memory) from a storage unit 713. The RAM 703 also has data and soforth stored therein necessary for the CPU 701 to execute various typesof processing.

The CPU 701, ROM 702, and RAM 703 are mutually connected via a bus 704.This bus 704 is also connected to an input/output interface 710.

The input/output interface 710 is connected to an input unit 711 made upof a keyboard, mouse, and the like, an output unit 712 made up of adisplay made up of a CRT (Cathode Ray Tube) or LCD (Liquid CrystalDisplay) or the like and a speaker or the like, a storage unit 713 madeup of a hard disk or the like, and a communication unit 714 made up of amodem or the like. The communication unit 714 performs communicationprocessing via a network which includes the Internet.

The input/output interface 710 also is connected to a drive 715 asneeded, and a removable medium 721 such as a magnetic disk, opticaldisk, magneto-optical disk, or semiconductor memory is mounted asappropriate, and a computer program read out there from is installed inthe storage unit 713 as needed.

In the case of executing the above-described series of processing withsoftware, a program making up the software thereof is installed from anetwork or recording medium.

This recording medium is made up, separately from the device main unit,not only of a removable media 721 made up of a magnetic disk in which aprogram is recorded (including a flexible disk), optical disc (includingCD-ROM (Compact Disc-Read Only Memory) and DVD (Digital VersatileDisc)), magneto-optical disc (includes MD (Mini Disc)), or semiconductormemory, distributed in order to distribute the program to users, but isalso made up of a ROM 702 or a hard disk included in the storage unit713 in which a program is recorded, so as to distribute to users in thestate of being built into the device main unit beforehand.

Note that the program that the computes executes may be a program forprocessing to be performed in a time-series manner in the sequencedescribed in the present specification, or may be a program forprocessing to be performed in parallel or at a necessary timing such asupon call-up.

Also, according to the present Specification, it goes without sayingthat the steps describing the program recorded in the recording mediuminclude processing performed in a time-series manger according to thedescribed sequence, but even if not necessarily processed in atime-series manner, also includes processing that is executed inparallel or individually.

Also, according to the present Specification, the system indicates theentirety of equipment made up of multiple devices (apparatuses).

Also, with the above description, the configuration described as onedevice (or processing unit) may be configured as multiple devices (orprocessing units). Conversely, a configuration described above asmultiple devices (or processing units) may be configured so as to beintegrated into one device (or processing unit). Also, a configurationother than that described above may be added to the configuration of thevarious devices (or various processing units). Further, as long as theoverall system configuration and operations are practically the same, aportion of a configuration of a certain device (or processing unit) maybe included in the configuration of another device (or other processingunit). That is to say, embodiments of the present invention are notlimited to the embodiments described above, and various types ofmodifications may be made without departing of the essence of thepresent invention.

REFERENCE SIGNS LIST

-   100 information processing system-   101 recording device-   102 playing device-   103 output device-   151 imaging unit-   152 user specification accepting unit-   153 gamut conversion control unit-   154 gamut conversion processing unit-   155 restoration metadata generating unit-   156 recording unit-   161 playing unit-   162 restoration gamut conversion control unit-   163 restoration processing unit-   164 gamut conversion processing unit-   165 communication unit-   171 restoration conversion state confirming unit-   172 information exchange unit-   173 determining unit-   181 communication unit-   182 information providing unit-   183 restoration processing unit-   184 gamut conversion processing unit-   185 output unit-   212 information providing unit-   222 restoration gamut conversion control unit-   231 restoration conversion state confirming unit-   232 information exchange unit-   233 determining unit

1. (canceled)
 2. An information processing device comprising: circuitryconfigured to control: confirming a determining condition forcontrolling execution of restoration processing that returns at least aportion of a gamut of an image to a state before the image is subjectedto gamut conversion; and executing said restoration processing, based ona confirmation result from the confirming.
 3. The information processingdevice according to claim 2, wherein the circuitry is configured tocontrol confirming whether or not, as said determining condition, saidinformation processing device itself and other information processingdevice are each able to execute said restoration processing.
 4. Theinformation processing device according to claim 3, wherein thecircuitry is configured to control, in a case that only said informationprocessing device itself is confirmed as able to execute saidrestoration processing, causing said information processing deviceitself to execute said restoration processing.
 5. The informationprocessing device according to claim 3, wherein the circuitry isconfigured to control, in a case that only said other informationprocessing device is confirmed as able to execute said restorationprocessing, causing said other information processing device to executesaid restoration processing.
 6. The information processing deviceaccording to claim 3, wherein the circuitry is configured to control, ina case that both of said information processing device itself and saidother information processing device are confirmed as unable to executesaid restoration processing, omitting said restoration processing. 7.The information processing device according to claim 3, wherein thecircuitry is configured to control, in a case that both of saidinformation processing device itself and said other informationprocessing device are confirmed as able to execute said restorationprocessing, confirming a selection condition for selecting a favorabledevice to perform said restoration processing.
 8. The informationprocessing device according to claim 7, wherein the circuitry isconfigured to control: confirming whether or not, as said selectioncondition, a manufacturing source of said other information processingdevice matches said information processing device; in a caseconfirmation is made that the manufacturing source of said otherinformation processing device matches said information processingdevice, causing said other information processing device to execute saidrestoration processing; and in a case confirmation is made that themanufacturing source of said other information processing device doesnot match said information processing device, causing said informationprocessing device itself to execute said restoration processing.
 9. Theinformation processing device according to claim 7, wherein thecircuitry is configured to control: confirming whether or not, as saidselection condition, an algorithm of said restoration processing of saidother information processing device is newer than an algorithm of saidrestoration processing of said information processing device; in a caseconfirmation is made that the algorithm of said restoration processingof said other information processing device is newer than the algorithmof said restoration processing of said information processing device,causing said other information processing device to execute saidrestoration processing; and in a case confirmation is made that thealgorithm of said restoration processing of said other informationprocessing device is not newer than the algorithm of said restorationprocessing of said information processing device, causing saidinformation processing device itself to execute said restorationprocessing.
 10. The information processing device according to claim 7,wherein the circuitry is configured to control: confirming whether ornot, as said selection condition, said other information processingdevice is able to execute said restoration processing as to a high-toneimage that is higher than a predetermined tone; in a case confirmationis made that said other information processing device is able to executesaid restoration processing as to said high-tone image, causing saidother information processing device to execute said restorationprocessing; and in a case confirmation is made that said otherinformation processing device is not able to execute said restorationprocessing as to said high-tone image, causing said informationprocessing device itself to execute said restoration processing.
 11. Theinformation processing device according to claim 2, wherein thecircuitry is configured to control: confirming whether or not, as saidselection condition, restoration metadata exists which includesinformation necessary for said restoration processing of said image; andin a case confirmation is made that said restoration metadata of saidimage exists, causing said information processing device itself or saidother information processing device to execute said restorationprocessing.
 12. The information processing device according to claim 2,wherein the circuitry is configured to control: second confirming whichconfirms a selection condition to select a favorable device forperforming gamut conversion processing to convert the gamut of saidimage to a desired gamut; executing said gamut conversion processing,based on a confirmation result from said second confirming.
 13. Theinformation processing device according to claim 12, wherein thecircuitry is configured to control: confirming whether or not, as saidselection condition, a manufacturing source of said other informationprocessing device matches that of said information processing device,whether or not an algorithm of said gamut conversion processing of saidother information processing device is newer than an algorithm of saidgamut conversion processing of said information processing device, orwhether or not said other information processing device is able toexecute said gamut conversion processing as to a high-tone image that ishigher than a predetermined tone; in a case confirmation is made thatthe manufacturing source of said other information processing devicematches that of said information processing device, in a caseconfirmation is made that the algorithm of said gamut conversionprocessing of said other information processing device is newer than thealgorithm of said gamut conversion processing of said informationprocessing device, or in a case confirmation is made that said otherinformation processing device is able to execute said gamut conversionprocessing as to said high-tone image, causing said other informationprocessing device to execute said gamut conversion processing; and in acase confirmation is made that the manufacturing source of said otherinformation processing device does not match that of said informationprocessing device, in a case confirmation is made that the algorithm ofsaid gamut conversion processing of said other information processingdevice is not newer than the algorithm of said gamut conversionprocessing of said information processing device, or in a caseconfirmation is made that said other information processing device isunable to execute said gamut conversion processing as to said high-toneimage, causing said information processing device itself to execute saidgamut conversion processing.
 14. The information processing deviceaccording to claim 2, wherein the circuitry is configured to control:reading out said image from a recording medium; a second confirmingwhich confirms a determining condition for controlling execution of saidrestoration processing as to said image read out from said recordingmedium; the execution of said restoration processing as to aid imageread out from said recording medium, based on a confirmation result fromthe second confirming; and transmitting said image read out from saidrecording medium or an image subjected to said restoration processing,to said other information processing device.
 15. The informationprocessing device according to claim 2, wherein the circuitry isconfigured to control: outputting said image, receiving said imagetransmitted from said other information processing device; a secondconfirming which confirms determining conditions for controllingexecution of said restoration processing as to said image received;executing said restoration processing as to said image received, basedon a confirmation result from the second confirming; and outputting saidimage received or said image subjected to said restoration processing.16. An information processing method comprising: controlling, by aprocessing device, confirming determining a condition for controllingexecution of restoration processing which returns at least a portion ofa gamut of an image to a state before the image is subjected to gamutconversion; and executing said restoration processing based on aconfirmation result from the confirming.
 17. A non-transitory recordingmedium configured to store a program executable by a computer, theprogram comprising: confirming determining a condition for controllingexecution of restoration processing which returns at least a portion ofa gamut of an image to a state before the image is subject to gamutconversion; and executing said restoration processing based on aconfirmation result from the confirming.
 18. The information processingdevice of claim 2, wherein the circuitry is configured to controlperforming communication of the image subjected to the gamut conversionbetween other information processing devices.